Fourteen New, Endemic Species Of Shrew (Genus Crocidura) From Sulawesi Reveal A Spectacular Island Radiation

BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY FOURTEEN NEW, ENDEMIC SPECIES OF SHREW (GENUS CROCIDURA) FROM SULAWESI REVEAL A SPECTACULAR ISLAND RADIATION JACOB A. ESSELSTYN, ANANG S. ACHMADI, HERU HANDIKA, MARK T. SWANSON, THOMAS C. GIARLA, AND KEVIN C. ROWE BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY Number 454, 108 pp., 43 figures, 18 tables Issued December 15, 2021 Copyright © American Museum of Natural History 2021 ISSN 0003-0090 FOURTEEN NEW, ENDEMIC SPECIES OF SHREW (GENUS CROCIDURA) FROM SULAWESI REVEAL A SPECTACULAR ISLAND RADIATION JACOB A. ESSELSTYN Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, LA ANANG S. ACHMADI Museum Zoologicum Bogoriense, Indonesian Institute of Sciences, Cibinong, West Java, Indonesia HERU HANDIKA Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, LA MARK T. SWANSON Museum of Natural Science and Department of Biological Sciences, Louisiana State University, Baton Rouge, LA THOMAS C. GIARLA Department of Biology, Siena College, Loudonville, NY KEVIN C. ROWE Sciences Department, Museums Victoria, Melbourne, Victoria, Australia 2 CONTENTS Abstract.............................................................................3 Introduction.........................................................................3 Materials and Methods .............................................................5 Results.............................................................................12 Field Collections, Identifications, and Morphological Variation .........................12 Mitochondrial Relationships and Diversity...........................................15 Nuclear Exon Phylogeny and Species Delimitation ....................................17 Ultraconserved Element Phylogenies................................................17 Species Accounts....................................................................17 Long-Tailed Group and Elongata Subgroup ..........................................19 Rhoditis Group...................................................................41 Small-Bodied Group ..............................................................82 Thick-Tailed Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 Ordinary Group ..................................................................71 Discussion .........................................................................90 Data Completeness ...............................................................92 Phylogenetic Relationships and the Tempo of Diversification...........................92 Local Species Richness and Species Geographic Ranges................................93 Geographic Patterns of Morphological Diversity and Sympatry .........................94 Regional Geography of Shrew Diversity .............................................96 Within-Island Diversification Processes..............................................96 Conclusion .........................................................................97 Acknowledgments...................................................................97 References..........................................................................98 Appendix: Gazetteer ............................................................... 105 3 ABSTRACT After nearly a decade of field inventories in which we preserved voucher specimens of the small terrestrial mammals of Sulawesi, we combined qualitative and quantitative analyses of morphological traits with molecular phylogenetics to better understand the diversity of shrews (Soricidae: Crocidura) on the island. We examined the morphology of 1368 specimens and obtained extensive molecular data from many of them, including mitochondrial DNA sequences from 851 specimens, up to five nuclear exons from 657 specimens, and thousands of ultraconserved elements from 90 specimens. By iteratively testing species limits using distinct character datasets and appropriate taxon sampling, we found clear, mostly consistent evidence for the existence of 21 species of shrews on Sulawesi, only seven of which were previously recognized. We divide these 21 species into five morphogroups, provide emended diagnoses of the seven previously named species, and describe 14 new species. The Long-Tailed Group contains Crocidura caudipilosa, C. elongata, C. microelongata, new species, and C. quasielongata, new species; the Rhoditis Group contains C. rhoditis, C. pseudorhoditis, new species, C. australis, new species, and C. pallida, new species; the Small-Bodied Group contains C. lea, C. levicula, C. baletei, new species, C. mediocris, new species, C. parva, new species, and C. tenebrosa, new species; the Thick-Tailed Group contains C. brevicauda, new species and C. caudicrassa, new species; and the Ordinary Group contains C. musseri, C. nigripes, C. normalis, new species, C. ordinaria, new species, and C. solita, new species. Documenting these endemic species reveals a local radiation (20 of the 21 species are members of an endemic clade) in which elevational gradients played a prominent role in either promoting speciation, or at a minimum, fostering the cooccurrence of phenotypically similar species. As now understood, the species-level diversity of Crocidura on Sulawesi is nearly three times the known diversity of any other insular shrew fauna. This study highlights the fact that if we wish to understand the true extent of biodiversity on Earth, large-scale, vouchered organismal inventories followed up with thorough examinations of genetic, morphological, and geographic traits are sorely needed in montane tropical regions, even for purportedly well-studied groups such as mammals. This publication has been registered in ZooBank: urn:lsid:zoobank.org:pub:7982B923-4CDC-44ED-A598-8651009DC7CC INTRODUCTION As the foundation of biodiversity knowledge, taxonomy is essential to our understanding of evolutionary and ecological processes (Mace, 2004; Patterson et al., 2010; Thomson et al., 2018). Species are recognized and counted when they are named by nomenclatural acts, and as a whole, these names represent the fundamental units of much biological research. Errors in taxonomy obscure processes such as trait evolution, population dynamics, community ecology, and beyond. Despite the great need, the taxonomy of many groups of organisms in most biogeographic regions remains woefully inadequate. Taxonomic resolution and accuracy are especially limited in tropical regions, where biodiversity inventories have not resulted in the preservation of enough specimens sampled across existing ecogeographic variation to allow for comprehensive taxonomic revisions. Although these limitations might surprise the nonspecialist, they are painfully apparent to taxonomists and exist even for many mammalian groups (e.g., bats, rodents, and shrews) and biogeographic regions (especially mountainous tropical domains like Madagascar, Wallacea, and the Andes; Burgin et al., 2018). Shrews (family Soricidae) are a diverse group of mammals (461 species; Burgin et al., 2018), with a nearly global distribution. They are found on all continents except Australia and Antarctica. Within this family, the genus Crocidura is distributed across Africa and Eurasia, reaching 4 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 its eastern limit in the Philippines and Indonesia. Crocidura currently contains 205 species, far more than any other mammalian genus (Burgin et al., 2018). This unusual level of richness is an implicit recognition of the conservative morphology of these animals. Over the approximately 6–8 million years since the origin of this genus (Dubey et al., 2007; Hutterer et al., 2018), little morphological diversity has accumulated. As such, constructing a taxonomy for these shrews that adequately estimates the true number of species and their limits has proven difficult (e.g., Giarla and Esselstyn, 2015; Stanley et al., 2015; Demos et al., 2017). In Indonesia, near the eastern geographical limit of Crocidura, lies the oceanic island of Sulawesi. This island is large (174,600 km2), tropical (1.7° N to 5.8° S latitude), and mountainous (six peaks exceed 3000 m). Perhaps Sulawesi’s most conspicuous feature is its peculiar shape, which comprises a central area and four peninsulas that give it a K-like shape (fig. 1). The island’s fauna is remarkably rich in murine rodents (Rowe et al., 2016a, 2019), macaques (Fooden, 1969), and many other animal groups (e.g., Riedel and Narakusumo, 2019). The complexity of Sulawesi’s geological history (Nugraha and Hall, 2018), its extensive ecogeographic variation (Whitten et al., 1987), and its tropical location are all factors that helped foster high levels of biodiversity. Researchers have also documented consistent geographical patterns of genetic partitioning among several ecologically and phylogenetically disparate animal taxa (e.g., toads, primates, and mice; Evans et al., 2003, 2008; Merker et al., 2009; Giarla et al., 2018; Handika et al. 2021). The consistent locations of interand intraspecific genetic breaks on Sulawesi have led biologists to delineate several areas of endemism (Evans et al., 2003), which are largely defined by the boundaries between the central part of the island and the peninsulas. In total, seven areas of endemism are recognized: the north-east, north-central, and north-west areas of endemism are all located on the northern peninsula; the central portion of the island is referred to as the west-central area of endemism; and the eastern, southeastern, and southwestern peninsulas are the east-central, south-east, and south-west areas of endemism, respectively (fig. 1). Some research has suggested that the westcentral area of endemism could be divided into two areas separated by the Palu-Koro Fault (Merker et al., 2009), but here we follow the more standard definition of seven areas of endemism (Evans et al., 2003). As with several other groups, the shrew fauna on Sulawesi is diverse. Only the genus Crocidura is naturally present (the nonnative Suncus murinus may be found around human habitations), and seven species are currently recognized, but that figure is an underestimate; several studies have reported or suggested the presence of undescribed and unidentified species (e.g., Musser, 1982, 1987; Ruedi, 1995; Eldridge et al., 2018; Esselstyn et al., 2019). Among the seven currently documented species, six form a clade, while the remaining taxon (C. nigripes) is more closely related to species on other islands to the west (Ruedi et al., 1998; Esselstyn et al., 2009, 2019; Hinckley et al., 2021). This suggests that most of Sulawesi’s shrew diversity arose through in situ diversification after the arrival of a single colonizing ancestor (Ruedi et al., 1998). The apparent dominance of in situ diversification as the main process generating diversity raises questions regarding what within-island mechanisms (e.g., geographic, ecological, behavioral, genetic, etc.) might have fostered speciation. Previous studies of Sulawesi’s fauna have suggested that geological events, marine incursions, and climatic variation associated with elevational gradients offer plausible explanations for the high diversity and consistent genetic partitioning of a variety of organisms, including shrews (Evans et al., 2003, 2008; Merker et al., 2009; Hawkins et al., 2016; Eldridge et al., 2018; Giarla et al., 2018). In this paper we investigate the diversity of shrews from Sulawesi using a large set of new collections made between 2010 and 2018. We combine extensive genetic data with qualitative 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 5 and quantitative phenotypic information from new and old specimens alike to resolve species limits and describe new taxa. In revising the taxonomy, we identify patterns associated with species geographic ranges, local species richness, and phylogenetic relationships that highlight opportunities for a better understanding of the ecological and evolutionary processes that promote and maintain biological diversity. Materials and Methods Species delimitation: Many pages have been written on the topic of species concepts, but relatively little of it is directly applicable to empirical problems (Sites and Marshall, 2003; Cadena et al., 2017). In an applied sense, and consistent with a variety of theoretical concepts, we anticipate that, more often than not, species will have genetic or morphological autapomorphies and cohesive geographic ranges. Therefore, we examined variation in morphology, mitochondrial DNA, and nuclear DNA, while considering the geographic distribution of specimens that are similar genetically and morphologically. When the preponderance of data suggests that a group of specimens is geographically, genetically, and morphologically cohesive, we recognize these specimens as representing a species. The species we identified should be consistent with many theoretical concepts, including the biological (Mayr, 1942, 1957), evolutionary (Simpson, 1961; Wiley, 1981), and general lineage (de Queiroz, 2007) concepts, because their definitions all rely on isolation in one form or another and predict the origin of unique traits and trait combinations. NE NC EC NW WC SW SE 0° 10°N 20°N 120°E110°E 130°E 100 km AB118°E 1.5°N 0° 1.5°S 0–1000 m >2000 m 1000–2000 m 4.5°S 3°S 6°S 120°E 122°E 124°E CHINA VIETNAM PHILIPPINES Temboan Ambang Buliohuto Dako Tompotika Recent sample sites Miller and Hollister (1921) type localities Katopasa Pinedapa Rorekatimbo Torompupu Gandang Dewata Balease Wasponda Tolala Mekongga Latimojong Bawakaraeng Luzon Mindanao MALAYSIA Borneo Java Sumatra km500 FIG. 1. Maps of A, Southeast Asia and B, Sulawesi showing topographical relief and the approximate boundaries (thick black lines) between areas of endemism (sensu Evans et al., 2003). Two-letter abbreviations in dark gray typeface identify the north-east (NE), north-central (NC), north-west (NW), west-central (WC), eastcentral (EC), south-west (SW), and south-east (SE) areas of endemism. Diamonds label localities where we, or others, have collected shrew specimens since 2010 with the mountain (or locality) name. Stars indicate type localities (Temboan and Pinedapa) from Miller and Hollister (1921). The type localities for the only two Crocidura described from the island since 1921 are Mt. Rorekatimbo (west-central area of endemism) for C. musseri Ruedi (1995) and Mt. Dako (north-west area of endemism) for C. caudipilosa Esselstyn et al. (2019). 6 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Specimen acquisition: Beginning in 2010, we and others collected specimens of small terrestrial mammals in the vicinities of 12 mountains and two lowland areas that together represent six of the seven areas of endemism on Sulawesi (all but the north-central area of endemism were sampled). While these 14 sampling areas varied widely in the extent of trapping effort and elevational sampling range, we hereafter refer to them as “localities.” We use “sites” to refer to specific places within localities where relevant. The surveyed mountains include three on the northern peninsula (Mt. Ambang of the northeast area of endemism, and Mts. Buliohuto and Dako of the north-west area of endemism), two on the eastern peninsula (Mts. Tompotika and Katopasa of the east-central area of endemism), one on the southeastern peninsula (Mt. Mekongga of the south-east area of endemism), one on the southwestern peninsula (Mt. Bawakaraeng of the south-west area of endemism), and five that are spread across the central core of the island (Mts. Latimojong, Gandang Dewata, Rorekatimbo, Balease, and Torompupu of the west-central area of endemism; fig. 1). Most of the specimens we studied are from these 12 mountains, but we also obtained a few samples from two lowland areas that are not connected to large mountains. Both lowland localities (Wasponda and Tolala) are near the boundary between the west-central and south-east areas of endemism. We included samples from Salu Tiwo, a partially forested lowland area northwest of Mt. Gandang Dewata, with that mountain locality (fig. 1). The specimen material from these 14 localities is deposited at the Museum Zoologicum Bogoriense, Bogor (MZB), Field Museum of Natural History, Chicago (FMNH), Louisiana State University Museum of Natural Science, Baton Rouge (LSUMZ), University of California Museum of Vertebrate Zoology, Berkeley (MVZ), Museum of Wildlife and Fish Biology at the University of California, Davis (MWFB), and Museums Victoria, Melbourne (NMV). Some specimens have had parts shared between institutions and thus are cataloged at multiple institutions. All animal handling was conducted consistent with the guidelines of the American Society of Mammalogists (Sikes et al., 2016) and approved by our relevant institutional committees. All field research was also approved by relevant Indonesian authorities. Most shrew specimens were taken in pitfall traps. Buckets were usually 20 or 30 L in volume and connected by drift fence assembled from strips of sheet plastic and placed in lines of 5–15 traps along traversable terrain, nearly always in forested habitat. At Mt. Balease, we also used smaller buckets (3 L) placed such that natural objects, such as downed logs and large rocks, served as drift fences. Trapping at all sites also incorporated extensive use of other trap types (e.g., Victor snap traps, Museum Specials, and Sherman live traps), which produced a few additional shrew specimens at each locality. Most specimens were prepared as fluid vouchers, fixed initially in formalin, and subsequently stored in 70% ethanol, or as traditional museum study skins with cleaned skulls and skeletons. Skulls were often removed from fluid carcasses prior to fixation with formalin. Skeletal material was cleaned by dermestid beetles at the various museums. Tissue samples were preserved for genetic analysis by either freezing in liquid nitrogen or fixation in ethanol or RNALater (SigmaAldrich), followed by storage at -80° C. We examined 1368 Crocidura specimens from Sulawesi, a total that includes the new specimens we collected, as well as older material available at some of the museums named above (MZB and FMNH) and at the National Museum of Natural History, Washington D.C. (USNM); American Museum of Natural History, New York (AMNH); Museum of Southwestern Biology, Albuquerque (MSB); and the Naturalis Biodiversity Center, Amsterdam (RMNH). These collections added several localities to our geographic sampling, but most involved relatively limited numbers of shrew specimens. The exceptions are the extensive shrew holdings at AMNH, collected by G.G. Musser, Boeadi of Museum Zoologicum Bogoriense, and others during the 1970s on Mt. Nokilalaki and vicinity (ca. 15 km west of Mt. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 7 Rorekatimbo, which is included in our more recent sampling) as well as those housed primarily at USNM and collected by H.C. Raven and colleagues in 1916 and 1918 at Temboan, Gimpoe, and Pinedapa (fig. 1). The early Raven collections include the types of five (Crocidura elongata, C. lea, C. levicula, C. nigripes, and C. rhoditis) of the seven currently recognized species of Sulawesi shrew (Miller and Hollister, 1921). The remaining two species (C. musseri and C. caudipilosa) were described by Ruedi (1995) and Esselstyn et al. (2019). A complete, georeferenced list of localities from which we examined specimens for this study is provided in the appendix. General approach to determining species diversity, limits, and relationships: We sought to maximize information content and dataset independence, while keeping research costs (time and money) manageable. We used independent datasets to compare and reconcile conclusions based on each set. As such, our DNA sequencing goal was to obtain one mitochondrial locus and several nuclear genes from multiple individuals of every species found at each locality, while also obtaining thousands of loci from at least two representatives of each potential species of shrew. This data-collection strategy allowed us to formulate initial hypotheses of species boundaries using mitochondrial sequences and morphological variation, evaluate whether analyses of these two datasets lead to similar conclusions, reconcile any differences between them and, finally, test the resulting putative species limits using a few nuclear genes from hundreds of specimens and thousands of loci from several dozen specimens. Our estimates of species limits focused on the specimens we collected because these represent relatively large series with both phenotypic and genetic data from individual localities. After formulating hypothesized species limits using our recently collected material, we then attempted to identify older specimens collected by others, and these comparisons relied almost entirely on morphological traits and geography. However, to determine which species represented among our new collections were synonymous with previously named taxa, we also attempted to collect genetic information from the type series of four species named by Miller and Hollister (1921). We did not include Crocidura nigripes in this sequencing effort because it is phenotypically distinctive and phylogenetically distant from other Sulawesi taxa. More recently described species (C. musseri and C. caudipilosa) have published genetic data available from the type series (Ruedi et al., 1998; Esselstyn et al., 2019), and we used those published sequences in our inferences. Morphological data collection and analysis: Our workflow started with identifying the morphospecies represented at each of the 14 localities sampled in this study and assigning as many specimens as possible to these putative, preliminary taxa. Morphospecies were distinguished using a combination of qualitative and quantitative morphometric traits from skulls and external anatomy. We then sought to understand whether these morphospecies were consistent with mtDNA clades (see methods below) within each locality and which morphospecies from different localities are potentially conspecific (i.e., genetically similar members of the same mtDNA clade). Whenever our initial morphospecies differed from the possible species suggested by mtDNA clusters, we reexamined the morphology. These reexaminations led us to identify a few additional, morphologically similar or cryptic putative species within localities. For input to this workflow, we gathered standard external measurements (in millimeters, mm: total length, tail length, hind-foot length including the claws, ear length) and mass (in grams, g) from museum databases, specimen tags, and the field notes of collectors for all shrew specimens we could find from Sulawesi. We calculated head-and-body length by subtracting tail length from total length for all specimens. For specimens with clean, undamaged skulls, J.A.E. measured 12 craniodental dimensions to the nearest 0.01 mm using digital calipers. These measurements comprise con- 8 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 dylo-incisive length (CIL), braincase breadth (BB), interorbital width (IOW), rostral length (RL), postpalatal depth (PPD), rostral width (RW), postpalatal length (PPL), condyle to glenoid fossa length (CGL), length of upper tooth row at crown (UTR), P4 to M3 crown length (P4–M3), labial M2 to M2 crown width (M2W), and palatal width (PW). Measurements were taken as in Ruedi (1995) and are illustrated in figure 2. We follow the dental homology hypothesized by Hutterer (2005) regarding the upper three unicuspids of Crocidura as I2, I3, and C and the lower unicuspid as i2. Accordingly, the dental formula of Crocidura is I3 C1 P1 M3 / i2 c1 p0 m3 = 28. Our quantitative analyses employed the measurements listed above, while our qualitative examinations focused on the overall shape and proportions of the skull and the color, texture, and pilosity of the tail, feet, and body. FIG. 2. Drawings of the skull of a Crocidura from a dorsal (upper), occlusal (middle), and lateral (lower) view showing the 12 cranial dimensions we analyzed. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 15 Tolala; fig. 1), all of which were assigned to species. Among the 1238 assigned specimens, each species was represented by between six and 156 specimens (59 ± 42). We found little evidence of sexual dimorphism in the well-sampled species, justifying our decision to combine the sexes in all morphometric analyses. Among 10 tests for sexual dimorphism, only one was significant at α = 0.05 (table 1). Mitochondrial relationships and diversity: Our mitochondrial gene tree containing 851 specimens showed clear clustering of tips that are largely consistent with the discontinuities we initially observed in morphological characters within localities. Examples where cytochrome b suggested we had mistakenly lumped cryptic species in our intitial morphological delimitations include taxa subsequently recognized in this report as Crocidura rhoditis and C. pseudorhoditis on Mt. Ambang; C. solita and C. ordinaria on Mt. Gandang Dewata; C. lea and C. baletei on Mt. Dako (“pale lea” and “dark lea” in Esselstyn et al., 2019); and between Elongata Subgroup members (defined below) at multiple localities. While the tip-level clusters in the cytochrome b gene tree are generally well supported, older relationships are almost entirely unsupported (fig. 4; supplementary data S2, available online: https://doi.org/10.5531/sd.sp.52). Our other mitochondrial gene tree, which was inferred from 14,007 nucleotides, but only 83 individuals (82 from Sulawesi; 1–8 per species), is similar in overall shape and topology, with tip clusters well supported, but again, the backbone relationships are largely unresolved (fig. 5). Intraand interspecific mitochondrial distances provide clear evidence of a barcode gap (e.g., Hebert et al., 2003; Puillandre et al., 2012) in our data. Although interspecific distances are far more numerous, distinct intraand interspecific peaks in frequency are evident (fig. 6). Most intraspecific Jukes-Cantor distances are <0.04, but seven species contain maximum intraspecific distances >0.05 (fig. 4; supplementary data S3– S5, available online: https://doi.org/10.5531/sd. sp.52). The lowest mean interspecific distance in our dataset is 0.047, found between both Crocidura mediocris and C. parva, and C. caudipilosa and C. baletei. All other mean interspecific distances are >0.05 and the vast majority are >0.07 (fig. 6; supplementary data S3, available online: https://doi.org/10.5531/sd.sp.52). Among the species with the lowest interspecific mitochondrial distances, C. mediocris and C. parva have similar phenotypes and allopatric distributions, but C. caudipilosa and C. baletei have quite different morphologies and occur together on Mts. Dako and Buliohuto. Most species we define are monophyletic in both the cytochrome b and mitogenome gene trees. However, two species, Crocidura mediocris TABLE 1 Tests for Sexual Dimorphism in Five Species of Crocidura N(m)/N(f)aCondyloincisive lengthbBraincase breadthc t df p t df p C. pseudorhoditis 36/38 -0.747 71 0.46 -0.649 72 0.52 C. solita 21/19 -2.288 35 0.03 -1.887 37 0.06 C. caudipilosa 30/22 -0.704 38 0.48 -0.841 46 0.41 C. quasielongata 24/16 -0.38 28 0.71 -0.108 32 0.92 C. nigripes 37/38 -0.666 73 0.51 -0.667 73 0.51 a Number of males/number of females. b Results from Welch’s two-sample t-tests for condyloincisive length. c Results from Welch’s two-sample t-tests for braincase breadth. 16 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 0.04 substitutions/site 47 99 100 99 76 54 76 11 69 45 79 86 85 4 92 100 100 27 93 60 82 49 100 100 100 19 100 99 100 36 60 100 99 100 34 99 99 100 100 100 72 100 27 100 C. nigripes T = 32; L = 9; MI = 0.016 C. microelongata T = 60; L = 4; MI = 0.076 C. pallida T = 52; L = 8; MI = 0.097 C. levicula T = 44; L = 7; MI = 0.022 C. baletei T = 6; L = 2; MI = 0.012 C. tenebrosa T = 13; L = 1; MI = 0.00 C. caudipilosa T = 65; L = 9; MI = 0.029 C. normalis T = 2; L = 1; MI = 0.069 C. normalis T = 38; L = 4; MI = 0.069 C. mediocris T = 25; L = 3; MI = 0.052 C. mediocris T = 22; L = 2; MI = 0.052 C. parva T = 81; L = 1; MI = 0.016 C. musseri T = 20; L = 1; MI = 0.006 C. elongata T = 47; L = 4; MI = 0.059 C. brevicauda T = 4; L = 1; MI = 0.009 C. caudicrassa T = 14; L = 2; MI = 0.039 C. quasielongata T = 77; L = 10; MI = 0.094 C. australis T = 6; L = 1; MI = 0.026 C. ordinaria T = 46; L = 2; MI = 0.048 C. solita T = 80; L = 4; MI = 0.039 C. lea T = 16; L = 3; MI = 0.029 C. rhoditis T = 21; L = 2; MI = 0.013 C. pseudorhoditis T = 82; L = 5; MI = 0.069 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 17 FIG. 4. Maximum-likelihood estimate of the gene tree of Sulawesi Crocidura derived from an alignment of 851 individuals and 1111 characters from the mitochondrial gene cytochrome b. Bootstrap support is shown along branches. Clades corresponding to species are collapsed for ease of presentation. Tips are labeled with the species name, the number of tips (T), and number of localities (L), as labeled in figure 1, and the maximum intraspecific (MI) Jukes-Cantor distance calculated from a reduced alignment. Two species are paraphyletic and their respective, within-clade MI values are shown separately. For species described by Miller and Hollister (1921), the holotype or paratypes are included for C. elongata, C. lea, and C. rhoditis. Branch lengths between C. nigripes and other taxa are shortened for presentation. See supplementary data S2 for the full tree. and C. normalis, are paraphyletic. The paraphyly of C. normalis is well supported in both mitochondrial inferences, but these populations form a clade in our UCE inferences (see below). In contrast, the separation of C. mediocris into two allopatric clades received essentially no support (BS = 49) in the cytochrome b tree, but these divergent populations are united in a poorly supported clade in the mitogenome tree. The lack of monophyly in the mitochondrial gene trees for C. normalis and C. mediocris gave us some hesitation with regard to how we have delimited species. However, in both cases, the morphology of each allopatric intraspecific clade is similar. If these species are young, we might expect some ancestral polymorphisms to be retained, and this can lead to the inference of paraphyly (Maddison, 1997). As such, gene-tree paraphyly is not necessarily inconsistent with our species concept. Nuclear exon phylogeny and species delimitation: Our inference of phylogenetic relationships from the concatenated alignment of five exons and 642 individuals produced a tree with coherent tip clusters but a lack of resolution for most interspecific relationships (supplementary data S6, available online: https://doi.org/10.5531/ sd.sp.52), similar to the branch-length and nodesupport patterns derived from mitochondrial sequences. In this tree, all but four species are monophyletic. Crocidura mediocris and C. parva are reciprocally paraphyletic, as are C. solita and C. ordinaria. Crocidura normalis, which is paraphyletic in the cytochrome b inference is monophyletic and well supported by nuclear exons. Most of the species that are monophyletic in this analysis (17 taxa) are well supported, with bootstrap values >90 (supplementary data, S6). Multispecies coalescent tests of our hypothesized species limits using BPP on our five-locus nuclear dataset supported every putative species we tested with a posterior probability of 1.0 for each combination of parameter settings and taxon samples. Details of these analyses are presented in the species accounts below. Ultraconserved element phylogenies: Phylogenetic inferences using sequences from either 983 UCEs (75% threshold: average alignment length 719 bp, range 171–1524 bp) or 3940 UCEs (10% threshold: average alignment length 613 bp, range 101–1615 bp) from 90 samples from Sulawesi provided similar levels of resolution to our mitochondrial inferences (figs. 4, 5) near the tips of the tree and somewhat better resolution of interspecific relationships (figs. 7, 8). For instance, in our species-tree estimate (fig. 7), which treated individuals as “species” so that we could see which tips formed natural groups, we found that all species except Crocidura ordinaria, C. solita, C. mediocris, and C. parva are monophyletic, as we inferred from our analysis of five concatenated exons. Our concatenated UCE maximum likelihood inference produced the same result, except that C. parva is monophyletic in this tree (fig. 8). The monophyly of 17 or 18 of the delimited species supported their distinction, while the paraphyly noted in the remaining four or three species is consistent with multiple taxonomic hypotheses. SPECIES ACCOUNTS In the accounts that follow, we diagnose the seven species named by Miller and Hollister (1921), Ruedi (1995), and Esselstyn et al. (2019), and we describe 14 new species. Our results from 18 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 0.04 substitutions/site * Holotype ** Paratype Dako LSUMZ36907 Bawakaraeng NMV Z57223 Dako LSUMZ36906 Ambang LSUMZ39014 Katopasa NMV Z61813 Dako LSUMZ36980 Torompupu NMV Z61984 Ambang LSUMZ39311 C.brevicauda Latimojong MVZ237616 Gandang Dewata FMNH218726 Temboan FMNH43858** Ambang LSUMZ39031 Bawakaraeng MVZ237603 Mekongga MWFB8059 Rorekatimbo FMNH213246 Gandang Dewata NMV Z21981 Tompotika FMNH213357 Bawakaraeng NMV Z57044 Mekongga MWFB8130 Buliohuto LSUMZ38252 Balease FMNH210580 Bawakaraeng MVZ237610 Bawakaraeng NMV Z56314 Rorekatimbo FMNH213158 Gandang Dewata FMNH218989 Bawakaraeng NMV Z56319 Latimojong FMNH213005 Bawakaraeng MZB40991 Dako LSUMZ36946 Ambang LSUMZ39050 Balease FMNH210569 Gandang Dewata FMNH218776 Tompotika FMNH213341 Latimojong FMNH212990 Gandang Dewata FMNH218607 Buliohuto LSUMZ38292 Katopasa MZB39871 Rorekatimbo FMNH213202 Rorekatimbo FMNH213263 Buliohuto LSUMZ38254 Gandang Dewata MZB34804 Gandang Dewata MZB34793 Latimojong FMNH213064 Buliohuto LSUMZ38289 Tompotika FMNH213366 Ambang LSUMZ39025 Rorekatimbo FMNH213184 Ambang LSUMZ39016 Rorekatimbo FMNH213271 Latimojong FMNH213015 Mekongga MWFB8154 Balease FMNH210546 Latimojong FMNH213011 Buliohuto LSUMZ38284 C. sibirica Torompupu LSUMZ39446 Dako LSUMZ36949 Dako LSUMZ36937 Torompupu NMV Z62193 Salu Tiwo FMNH218704 Buliohuto LSUMZ38253 Buliohuto LSUMZ38264 Salu Tiwo FMNH218615 Ambang LSUMZ39273 Dako LSUMZ36951 Mekongga MWFB8134 Mekongga MWFB8151 Gandang Dewata MZB38473 Gandang Dewata MZB34871 Temboan USNM217535** Gandang Dewata FMNH218546 Katopasa NMV Z61792 Temboan USNM217554** Temboan USNM217552** Torompupu MVZ238107 Balease FMNH210608 Rorekatimbo FMNH213253 Ambang LSUMZ39038 Temboan USNM217553* Balease FMNH210559 Gandang Dewata FMNH218770 Tompotika FMNH213346 Katopasa NMV Z62395 45 92 34 92 85 82 27 91 46 94 89 27 85 64 81 35 56 92 C. caudipilosa C. normalis C. mediocris C. parva C. baletei C. normalis C. tenebrosa C. levicula C. pallida C. rhoditis C. pseudorhoditis C. solita C. ordinaria C. australis C. quasielongata C. caudicrassa C. elongata C. lea C. nigripes C. musseri C. microelongata FIG. 5. Maximum likelihood estimate of the mitochondrial gene tree derived from an analysis of 14,007 characters (representing protein-coding and rRNA genes) from 83 samples. Bootstrap support values <95 are shown at nodes. Tips are labeled with the species, locality, and voucher number. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 19 morphometric and coalescent species delimitation analyses are also presented here, together with relevant nomenclatural details and explanations of species groupings. To facilitate taxonomic comparisons, we group taxa based on external morphology, providing a means to focus on the species that are the most challenging to distinguish in the field. Whereas these groups provide a consistent method for referring to morphologically similar taxa, most of them do not represent clades. Within groups, we first discuss previously described species, emending the original diagnoses of Miller and Hollister (1921), which were brief and for some species based on very few specimens. We then describe the new species we have identified, noting external and cranial traits as much as possible. When we make comparative statements without explicit reference to another species or group of species, these are made relative to all other congeneric species from Sulawesi. In each account, we present external measurements and weight recorded from the holotype in the format of “total length × tail length × hind-foot length × ear length = weight.” For each species, we list the most useful morphological traits for identifying species in supplementary data S7 (available online: https://doi.org/10.5531/sd.sp.52). We report type localities for each species verbatim (e.g., as reported in the original descriptions of previously recognized species, or as recorded in museum databases and field notes for the newly described species). As a result, we report the English province name for some species but the Indonesian province name for others. In our descriptions of geographic ranges, however, we consistently use English names for Indonesian provinces as follows: Sulawesi Utara (North Sulawesi), Gorontalo (Gorontalo), Sulawesi Tengah (Central Sulawesi), Sulawesi Barat (West Sulawesi), Sulawesi Selatan (South Sulawesi), and Sulawesi Tenggara (Southeast Sulawesi). The type localities published in Miller and Hollister (1921) lack details of provinces and lower administrative units. We therefore provide, following the verbatim type locality, additional details of current geopolitical units. In each species account, we also report the known elevational range with the minimum and maximum rounded to the nearest 100 m. Long-Tailed Group and Elongata Subgroup Four species on Sulawesi have tail lengths (75– 145 mm) greater than their head-and-body lengths (65–105 mm; fig. 9; table 2). We group these taxa (Crocidura caudipilosa, C. elongata, C. microelongata, and C. quasielongata) together for ease of description, not because of any close phylogenetic relationships (supplementary data S6). Crocidura caudipilosa differs from the other members of the Long-Tailed Group by its uniquely hirsute tail and its skull with typical width-to-length ratios (fig. 10; Esselstyn et al., 2019). The other species have long and narrow skulls, varying degrees of a long postpalatal region relative to skull length, unusually long and slender hind feet (HF nearly always between 17 and 23 mm), and a very long tail (usually >100 mm) largely lacking in bristles. We refer FIG. 6. Distribution of Jukes-Cantor distances from a character matrix with 812 samples, 312 nucleotides of cytochrome b, and no missing data. Character sampling, and to a lesser extent taxon sampling, was reduced to eliminate missing data. 0 20,000 40,000 0 0.05 0.10 0.15 0.20 JUKES−CANTOR DISTANCE COUNT interspecific intraspecific 20 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 0.8 Gandang Dewata MZB 34804 C. ordinaria Torompupu NMV Z62193 Palawanosorex muscorum FMNH 195240 Temboan USNM 217552** Ambang LSUMZ 39311 Dako LSUMZ 36907 Dako LSUMZ 36980 Mekongga MWFB 8154 Rorekatimbo FMNH 213158 C. ordinaria Gandang Dewata FMNH 218726 Buliohuto LSUMZ 38289 Rorekatimbo FMNH 213246 Buliohuto LSUMZ 38284 Gandang Dewata FMNH 218546 Torompupu MVZ 238107 Gandang Dewata FMNH 218770 Katopasa NMV Z62395 Gandang Dewata MZB 38473 C. solita Gandang Dewata NMV Z21981 Katopasa NMV Z61813 Dako LSUMZ 36937 Tompotika FMNH 213341 Latimojong MVZ 237633 Temboan USNM 217535** Tompotika FMNH 213366 Buliohuto LSUMZ 38264 Crocidura goliath FMNH 167692 Rorekatimbo FMNH 213271 Latimojong FMNH 213005 Diplomesodon pulchellum MVZ 179157 Bawakaraeng MVZ 237610 Bawakaraeng NMV Z56314 Temboan USNM 217554** Ambang LSUMZ 39050 Ambang LSUMZ 39273 Mekongga MWFB 8059 Ambang LSUMZ 39281 Rorekatimbo FMNH 213253 Balease FMNH 210546 Bawakaraeng MVZ 237603 Balease FMNH 210608 Rorekatimbo FMNH 213202 Ambang LSUMZ 39025 Dako LSUMZ 36946 Bawakaraeng NMV Z57223 Balease FMNH 210569 Rorekatimbo FMNH 213263 Buliohuto LSUMZ 38253 Latimojong FMNH 213015 Bawakaraeng NMV Z57044 Salu Tiwo FMNH 218704 Latimojong FMNH 213064 Latimojong MVZ 237632 Buliohuto LSUMZ 38252 Mekongga MWFB 8130 Buliohuto LSUMZ 38254 Mekongga MWFB 8134 Ambang LSUMZ 39031 Dako LSUMZ 36951 Balease FMNH 210580 Bawakaraeng MZB 40991 Latimojong MVZ 237616 Crocidura palawanensis FMNH 195224 Katopasa NMV Z61792 Temboan FMNH 43858** Tompotika FMNH 213346 Gandang Dewata FMNH 218776 Mekongga MWFB 8151 Scutisorex thori FMNH 219669 Ambang LSUMZ 39038 Dako LSUMZ 36906 Torompupu NMV Z61984 Crocidura batakorum KU 165320 Crocidura siberica TK 146501 Torompupu LSUMZ 39446 Ambang LSUMZ 39016 Temboan USNM 217553* Crocidura horsfieldii NK 10645 Tompotika FMNH 213357 Ambang LSUMZ 39278 Dako LSUMZ 36949 Ambang LSUMZ 39279 Ambang LSUMZ 39283 Gandang Dewata FMNH 218989 Katopasa MZB39871 Gandang Dewata MZB 34793 Torompupu MVZ 238110 Rorekatimbo FMNH 213184 Ambang LSUMZ 39271 Suncus murinus KU 164724 Salu Tiwo FMNH 218615 C. parva Bawakaraeng NMV Z56319 Buliohuto LSUMZ 38292 Latimojong FMNH 212990 Balease FMNH 210559 Ambang LSUMZ 39014 C. ordinaria Gandang Dewata MZB 34871 Latimojong FMNH 213011 Paracrocidura schoutedeni FMNH 167721 Gandang Dewata FMNH 218607 0.63 0.67 0.39 0.83 0.54 0.55 0.74 0.24 0.6 0.8 0.48 0.48 0.53 0.44 0.25 0.66 0.88 0.67 * Holotype ** Paratype C. nigripes C. lea C. elongata C. rhoditis C. musseri C. pallida C. caudicrassa C. brevicauda C. australis C. solita C. solita C. levicula C. normalis C. parva C. mediocris C. mediocris C. tenebrosa C. baletei C. caudipilosa C. pseudorhoditis C. microelongata C. quasielongata 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 21 to these three species as the Elongata Subgroup of the Long-Tailed Group. This subgroup designation reflects previous suggestions of the possible existence of multiple taxa contained within C. elongata (Ruedi, 1995; Eldridge et al., 2018; Esselstyn et al., 2019). However, despite their phenotypic similarities, none of these three species form a sister relationship in any of our phylogenetic analyses, nor are any sister to C. caudipilosa (figs. 4, 5, 7, 8). Backbone relationships, however, are unresolved and it remains plausible that some Elongata Subgroup members are sister species. Crocidura caudipilosa is broadly sympatric with Elongata Subgroup members and two members of the subgroup occur sympatrically at some sites (table 3). A principal components analysis of 12 cranial dimensions shows that one of the Elongata Subgroup members (C. microelongata) fills morphospace distinct from that occupied by the other two more similar species (fig. 11; table 4). Plots of individual cranial dimensions show a similar pattern (fig. 12). Crocidura caudipilosa Esselstyn et al., 2019 Crocidura caudipilosa Esselstyn et al., 2019: 1718. Original description. Holotype: MZB 41456 (= LSUMZ 36945), an adult male collected 8 March 2013 by J.L. Patton. The skin, skull, skeleton, and a tissue are held at MZB, while an additional frozen tissue is curated at LSUMZ. External measurements and weight recorded from the holotype are 182 mm × 98 mm × 19 mm × 9 mm = 12 g. Type locality: Indonesia, Sulawesi Tengah, Toli Toli, Malangga Selatan, Mt. Dako; 1.10642° N, 120.9106° E, 512 m elevation. Geographic distribution: Widespread on Sulawesi across most areas of endemism, with records from the west-central (Mts. Rorekatimbo and Torompupu, Central Sulawesi Province; Mt. Gandang Dewata, West Sulawesi Province; Mt. Latimojong, South Sulawesi Province), northwest (Mt. Dako, Central Sulawesi Province; Mt. Buliohuto, Gorontalo Province), north-east (Mt. Ambang, North Sulawesi Province), south-west (Mt. Bawakaraeng, South Sulawesi Province), east-central (Mt. Katopasa, Central Sulawesi Province), and south-east (Mt. Mekongga, Southeast Sulawesi Province) areas of endemism. The lack of records from the north-central area of endemism is almost certainly due to the lack of collecting effort in this region. Occurs over a wide elevational range from approximately 500 m on Mt. Buliohuto to at least 2600 m on Mt. Gandang Dewata (fig. 13; table 3). Abbreviated diagnosis: Esselstyn et al. (2019) made detailed comparisons to other Sulawesi species found on Mt. Dako, of the north-west area of endemism. Briefly, Crocidura caudipilosa is a slender grayish to brownish shrew with a hairy tail (fig. 14A) that is moderately longer than the head and body (table 2). The feet are brown in dorsal view, with paler digits. The skull is gracile, with rounded features and a weakly developed dentition (fig. 15). Summary statistics for measurements of material we refer to this species are provided in tables 2 and 5. Comparisons: This species is readily distinguished from all other Crocidura on Sulawesi by the density (combined number and length) of applied hairs on the tail (short hairs that lie close to the tail, not the longer bristles that typically project away from the tail on many species of Crocidura), but it is also distinguishable by various combinations of its body size, tail length relative to head-and-body length (fig. 9), gray to brown pelage, slight bicoloration (darker dorsum, paler venter), slender skull, and relatively small teeth. Its tail is shorter relative to headand-body length than in any of the Elongata Subgroup members, but longer (absolutely and relatively) than in any other congeneric species FIG. 7. Estimated species tree from analysis of 3940 ultraconserved element loci in ASTRAL. Samples from Sulawesi are labeled with the species name, locality, and catalog number. Asterisks indicate type specimens from Miller and Hollister (1921). Local posterior probabilities <0.95 are shown. Tip branch lengths are arbitrary. 22 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 94 64 94 63 63 69 51 93 70 71 93 27 84 63 50 0.02 Congosorex phillipsorum FMNH 177682 Myosorex geata FMNH 158299 Palawanosorex muscorum FMNH 195240 Scutisorex thori FMNH 219669 Suncus murinus KU 164724 Crocidura goliath FMNH 167692 Paracrocidura schoutedeni FMNH 167721 Diplomesodon pulchellum MVZ 179157 Crocidura siberica TK 146501 Crocidura horsfieldii NK 10645 Crocidura palawanensis FMNH 195224 Salu Tiwo FMNH 218704 Ambang LSUMZ 39279 Buliohuto LSUMZ 38292 C. nigripes Crocidura batakorum KU 165320 Torompupu MVZ 238107 Dako LSUMZ 36937 Tompotika FMNH 213341 Balease FMNH 210546 Mekongga MWFB 8130 Katopasa NMV Z61792 Torompupu NMV Z61984 Balease FMNH 210559 C. quasielongata Bawakaraeng MVZ 237610 Bawakaraeng NMV Z57223 Bawakaraeng MZB 40991 C. australis * Holotype ** Paratype Buliohuto LSUMZ 38289 Rorekatimbo FMNH 213246 Bawakaraeng NMV Z57044 Katopasa MZB39871 C. caudipilosa Rorekatimbo FMNH 213271 Tompotika FMNH 213346 Torompupu LSUMZ 39446 Tompotika FMNH 213357 C. levicula Mekongga MWFB 8154 Katopasa NMV Z61813 Mekongga MWFB 8151 Rorekatimbo FMNH 213184 Latimojong FMNH 213011 Gandang Dewata FMNH 218607 C. normalis Ambang LSUMZ 39273 Ambang LSUMZ 39025 Ambang LSUMZ 39271 C. tenebrosa Buliohuto LSUMZ 38264 Dako LSUMZ 36946 Dako LSUMZ 36951 C. baletei Balease FMNH 210569 Mekongga MWFB 8134 Torompupu MVZ 238110 Salu Tiwo FMNH 218615 C. mediocris Bawakaraeng NMV Z56314 Bawakaraeng MVZ 237603 Bawakaraeng NMV Z56319 C. parva Latimojong MVZ 237633 Latimojong MVZ 237632 Latimojong MVZ 237616C. brevicauda Gandang Dewata MZB 34804 Gandang Dewata MZB 34793 C. caudicrassa Ambang LSUMZ 39311 Dako LSUMZ 36980 Buliohuto LSUMZ 38284 Ambang LSUMZ 39281 Ambang LSUMZ 39031 Ambang LSUMZ 39278 Ambang LSUMZ 39283 C. pseudorhoditis Temboan USNM 217552** Temboan USNM 217554** Ambang LSUMZ 39050 Temboan FMNH 43858** Ambang LSUMZ 39038 C. rhoditis Dako LSUMZ 36907 Temboan USNM 217535** Buliohuto LSUMZ 38253 Buliohuto LSUMZ 38252 Dako LSUMZ 36906 Ambang LSUMZ 39016 Ambang LSUMZ 39014 C. elongata Buliohuto LSUMZ 38254 Temboan USNM 217553* Dako LSUMZ 36949 C. lea Rorekatimbo FMNH 213158 Gandang Dewata FMNH 218546 Gandang Dewata MZB 38473 Latimojong FMNH 213005 Latimojong FMNH 212990 C. microelongata Katopasa NMV Z62395 Tompotika FMNH 213366 Mekongga MWFB 8059 Balease FMNH 210608 Balease FMNH 210580 Gandang Dewata FMNH 218989 C. pallida Rorekatimbo FMNH 213253 Rorekatimbo FMNH 213263 C. musseri Torompupu NMV Z62193 C. ordinaria Gandang Dewata FMNH 218726 C. solita Gandang Dewata FMNH 218770 Gandang Dewata NMV Z21981 Rorekatimbo FMNH 213202 Latimojong FMNH 213064 Gandang Dewata FMNH 218776 Gandang Dewata MZB 34871 C. solita Latimojong FMNH 213015 C. solita C. ordinaria 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 23 on Sulawesi (fig. 9). Body size is considerably smaller than in C. elongata and C. quasielongata, but only slightly smaller than in C. microelongata (fig. 9). The skull and hind feet are not particularly elongate, as they are in members of the Elongata Subgroup. The ratio of braincase breadth to interorbital width is greater, on average, than in any other shrew species on Sulawesi, and considerably so compared to any of the Elongata Subgroup members (fig. 10). Comments: Individuals of Crocidura caudipilosa have been caught (NMV Z56802) and observed (NMV Z62413) climbing trees (Esselstyn et al., 2019). The extent of time this species spends in trees is unknown, but the possibility that some shrews on Sulawesi exploit arboreal resources is a potentially promising explanation for how so many species coexist on the island. Musser (1982: 81) reported collecting an undescribed species of Crocidura “in moss growing 8 feet above ground around a tree trunk.” However, he never described this species, and it is unclear whether he was referencing a member of the Long-Tailed Group or some other species. Crocidura caudipilosa is unusually widespread across Sulawesi, but Jukes-Cantor distances calculated from mtDNA sequences were <0.024 (fig. 4; supplementary data S3), suggesting recent, widespread movement of at least maternally inherited markers. Nuclear loci sampled from across the island show the same pattern, with variation detected at only five of 549 nucleotides among 56 sequences of apolipoprotein b, for instance. This species is sister to Crocidura levicula in our UCE- (figs. 7, 8) and nuclear exon-based phylogenies, although statistical support from the latter estimate was absent (supplementary data S6). Our mitochondrial estimates placed C. caudipilosa in an unresolved clade of several small, darkly colored species of shrew, among which C. levicula is included (figs. 4, 5). This clade, which was well supported by our UCE analyses, contained no other member species of the Long-Tailed Group (figs. 7, 8). Specimens examined: Mt. Ambang (LSUMZ 39243–39247), Mt. Bawakaraeng (MVZ 237625– 237627; NMV Z57152, Z57013, Z57043, Z57044), Mt. Buliohuto (LSUMZ 38288–38291, 38296, 38588, 38656; NMV C37746, C37815), Mt. Dako (LSUMZ 36940, 36942, 36945; NMV C37267, C37304, C37305, C37330, C37351), Mt Gandang Dewata (FMNH 218759–218762, 218768, 218983– 218986; MZB 34746, 34747, 34951, 34952), Mt. Katopasa (LSUMZ 39355–39357; MZB 39840, 39871, 39922; NMV C40186, C40219, C40220, Z61815, Z62413, Z62415), Mt. Latimojong (FMNH 213020–213028, 213427; MVZ 237612– 237615; MZB 41649; NMV C38591), Mt. Mekongga (MWFB 8158, 13512), Mt. Rorekatimbo (FMNH 213246–213248, 213441), Mt. Torompupu (LSUMZ 39358, 39359). Crocidura elongata Miller and Hollister, 1921 Crocidura elongata Miller and Hollister, 1921: 101. Original description. Crocidura “dark elongata” Esselstyn et al., 2019: 1715. Informal name. Holotype: USNM 217534, an adult male obtained by H.C. Raven on 1 August 1916. The specimen comprises a skin and skull. External measurements recorded from the type are 214 mm × 120 mm × 22 mm; no ear length or weight was recorded. Type locality: “Temboan (southwest from Tondano Lake), northeastern Celebes” (Miller and Hollister, 1921: 101; fig. 1). We estimate that the type locality is at 0.979° N, 124.605° E, 650 m elevation, which differs from other interpretations (e.g., Musser, 2014). See the gazetteer for a full explanation (appendix). Geographic distribution: Apparently restricted to the northern peninsula of Sulawesi, FIG. 8. Estimated phylogenetic relationships from a maximum likelihood analysis of 983 concatenated ultraconserved elements. Samples from Sulawesi are labeled with the species name, locality, and catalog number. Asterisks indicate type specimens from Miller and Hollister (1921). Ultrafast bootstrap values <95 are shown. 24 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ●● ●● ● ● ● ● ● ●● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ●● ●● ● ● ● ● ● ●●● ● ●●● ● ●● ● ● ● ●● ● ● ●●● ● ● ●● ●●●●● ● ● ●● ● ●●●●● ● ● ● ●●● ●●● N = 75 N = 54 N = 94 N = 110 N = 28 N = 97 N = 58 N = 44 N = 151 N = 5 N = 74 N = 94 N = 27 N = 17 N = 37 N = 51 N = 96 N = 33 N = 14 N = 8 N = 16 N = 75 N = 57 N = 94 N = 113 N = 29 N = 98 N = 58 N = 44 N = 152 N = 5 N = 74 N = 94 N = 27 N = 17 N = 37 N = 51 N = 94 N = 34 N = 14 N = 8 N = 15 N = 75 N = 55 N = 93 N = 111 N = 28 N = 95 N = 58 N = 44 N = 151 N = 5 N = 74 N = 94 N = 27 N = 17 N = 37 N = 51 N = 94 N = 33 N = 14 N = 8 N = 15 N = 77 N = 57 N = 95 N = 115 N = 30 N = 97 N = 56 N = 44 N = 154 N = 5 N = 79 N = 96 N = 27 N = 17 N = 38 N = 51 N = 97 N = 34 N = 13 N = 8 N = 16 C. caudipilosa C. elongata C. microelongata C. quasielongata C. musseri C. nigripes C. normalis C. ordinaria C. solita C. australis C. pallida C. pseudorhoditis C. rhoditis C. baletei C. lea C. levicula C. mediocris C. parva C. tenebrosa C. brevicauda C. caudicrassa SPECIES HIND-FOOT LENGTH Ordinary Small-Bodied ThickRhoditisLong-Tailed TAIL/HBL HEAD-AND-BODY LENGTHTAIL LENGTH 40 60 80 100 50 100 150 0.4 0.8 1.2 1.6 10 15 20 FIG. 9. Box plots showing variation in external measurements from all species of Sulawesi shrew. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. Species are grouped according to the species groups used in the text (Thick = ThickTailed Group). All measurements in mm. HBL = head-and-body length. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 31 N = 77 N = 57 N = 98 N = 118 N = 31 N = 88 N = 59 N = 45 N = 156 N = 6 N = 80 N = 98 N = 29 N = 17 N = 38 N = 51 N = 98 N = 34 N = 14 N = 8 N = 16 Long-Tailed Ordinary Rhoditis Small-Bodied Thick C. caudipilosa C. elongata C. microelongata C. quasielongata C. musseri C. nigripes C. normalis C. ordinaria C. solita C. australis C. pallida C. pseudorhoditis C. rhoditis C. baletei C. lea C. levicula C. mediocris C. parva C. tenebrosa C. brevicauda C. caudicrassa SPECIES ELEVATION (M) 0 1000 2000 FIG. 13. Elevational records of all species of Crocidura known from Sulawesi. Each point represents a specimen. For specimens associated with a minimum and maximum elevation, we used the center of the given elevational range. Sample sizes are given above the x-axis. Species are grouped according to the species groups used in the text (Thick = Thick-Tailed Group). 32 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 FIG. 14. Images showing the ventral surface of the left hind foot and dorsal surfaces of the tail base (approximately 1 cm from rump) and tail tip from the four members of the Long-Tailed Group: A, Crocidura caudipilosa, LSUMZ 36940; B, C. quasielongata, FMNH 218551; C, C. elongata, LSUMZ 39009; and D, C. microelongata, FMNH 212998. Scale bars represent 5 mm and apply to their nearest images within each panel. The thenar (T) and hypothenar (H) pads are labeled on panel B. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 33 elongata” by Esselstyn et al. (2019) because the authors were unable to determine if either of two long-tailed species on Mt. Dako represented true C. elongata. Mt. Dako is the only area where we found C. elongata occurring in syntopy with another member of the Elongata Subgroup (C. quasielongata). Despite the confusing history of specimens in this subgroup, none of our analyses suggested a sister relationship between any two of these species. In our UCE species-tree inference, C. elongata was moderately supported as the sister to C. rhoditis and C. pseudorhoditis (fig. 7), but in our mitogenome estimate it was placed as sister to C. lea, although without statistical support (fig. 5). Ruedi (1995) suggested a scansorial lifestyle for this species based on its long, naked-appearing tail and long hind feet. While this is certainly possible, direct evidence for a scansorial lifestyle is lacking, and these traits could be linked alternatively to a saltatorial locomotory style (Brosset, 1988). Some very limited evidence indicates that Crocidura caudipilosa, which has a long, but less extreme tail combined with a more typical hind-foot length, is a skilled climber (Esselstyn et al., 2019). For coalescent species delimitation results, see the Crocidura quasielongata account below. Specimens examined: Mt. Ambang (LSUMZ 39008–39013, 39015–39018, 39057, 39058, 39061, 39248–39251, 39257–39264, 39318; NMV C38009, C38032), Mt. Buliohuto (LSUMZ 38238, 38240, 38243–38247, 38251–38253; NMV C37742, C37752, C37760), Mt. Dako (LSUMZ 36905–36907, 36909, 36916, 36919, 36921, 36923, 36924, 36932; NMV C37248, C37249, C37303), Temboan (USNM 217534, 217535). Crocidura microelongata, new species LSID: urn:lsid:zoobank. org:act:015EFE9D-8AAC-433D-B563DD8855C43B00 Crocidura elongata Ruedi, 1995: 251. Misidentification. Holotype: MZB 43000 (= FMNH 213426), an adult male, collected on 1 March 2011 by J.A. Esselstyn. The specimen comprises a study skin, cleaned skull and skeleton, and frozen tissue samples. External measurements from the holotype are 206 mm × 111 mm × 20 mm × 10 mm = 12.5 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with another tissue sample retained at FMNH. Type locality: Indonesia, Sulawesi Selatan, Enrekang, Buntu Bato, Latimojong Village, Karangan, Mt. Latimojong, Bantanase; 3.40755° S, 120.0078° E, 2050 m. FIG. 15. Images showing dorsal, ventral, and lateral views of the skull and occlusal and lateral views of the dentary of Crocidura caudipilosa (FMNH 218986). 34 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Etymology: We combine “micro” with “elongata” because this species looks like a small version of C. elongata. Geographic distribution: This species is broadly distributed across western portions of the west-central area of endemism of Sulawesi. We identified populations from Mt. Latimojong, South Sulawesi Province; Mt. Gandang Dewata, West Sulawesi Province; and Mts. Torompupu and Rorekatimbo, Central Sulawesi Province (fig. 16). Recorded from approximately 700 m on Mt. Latimojong to 2600 m on Mt. Gandang Dewata. Most specimens are from areas >1500 m (fig. 13; table 3). Diagnosis: Crocidura microelongata is a somewhat large Crocidura with a long tail and long, slender hind feet and skull (tables 2, 5). The dorsal pelage is gray-brown overall, with individual hairs having a gray-brown base and brown tip (fig. 14D). The ventral pelage is more silver, comprising individual hairs with a dark gray base and silver tip. The mystacial vibrissae are dark proximally for a third of their length but white distally. The hind feet are long in absolute terms and relative to head-andbody length (figs. 9, 17). Dorsally, the feet are brown, abruptly transitioning to pinkish white near the base of the phalanges (in some specimens, it is a gradual transition). Ventrally, the hind feet are nearly white, but brown pigment is present around the lateral, posterior margin of the hind foot and around the base of the thenar and hypothenar pads TABLE 5 Descriptive Statisticsa for Craniodental Measurements (mm) for Species of the Long-Tailed Group of Sulawesi Crocidura C. caudipilosa C. elongata C. microelongata C. quasielongata Condyloincisive length 20.76 ± 0.624 (19.54–22.2) 44 24.35 ± 0.502 (23.15–25.46) 44 21.9 ± 0.749 (20.3–23.14) 35 24.25 ± 0.663 (22.32–25.23) 40 Braincase breadth 9.46 ± 0.232 (9.0–9.99) 44 9.73 ± 0.263 (9.16–10.22) 42 9.59 ± 0.229 (8.9–10.12) 33 9.81 ± 0.272 (9.26–10.48) 40 Interorbital width 4.47 ± 0.151 (4.1–4.84) 44 5.04 ± 0.17 (4.67–5.35) 44 5.01 ± 0.182 (4.69–5.35) 33 5.01 ± 0.179 (4.63–5.45) 41 Rostral length 8.32 ± 0.313 (7.59–9.05) 44 9.69 ± 0.276 (9.16-10.16) 44 8.59 ± 0.263 (7.91–9.03) 33 9.79 ± 0.307 (8.71–10.27) 41 Postpalatal width 3.77 ± 0.125 (3.52–4.05) 44 4.33 ± 0.13 (4.1–4.64) 44 4.21 ± 0.118 (4.0–4.48) 33 4.41 ± 0.156 (4.1–4.8) 41 Rostral width 2.92 ± 0.146 (2.63–3.22) 44 3.22 ± 0.116 (2.98–3.47) 44 3.03 ± 0.163 (2.62–3.4) 35 3.29 ± 0.178 (3.04–3.74) 41 Postpalatal length 9.44 ±0.321 (8.82–10.24) 43 11.1 ± 0.265 (10.44–11.84) 44 9.89 ± 0.329 (9.18–10.44) 35 11.0 ± 0.387 (10.29–11.75) 40 Condyle to glenoid fossa 8.25 ± 0.214 (7.89–8.76) 44 9.68 ± 0.211 (9.24–10.09) 44 8.85 ± 0.316 (8.17–9.36) 35 9.38 ± 0.26 (8.88–9.93) 40 Upper toothrow length 9.07 ± 0.283 (8.49–9.66) 44 10.6 ± 0.261 (10.07–11.15) 44 9.46 ± 0.296 (8.78–9.88) 35 10.6 ± 0.30 (9.65–11.03) 41 P4 to M3 length 4.77 ± 0.15 (4.44–5.07) 44 5.82 ± 0.154 (5.42–6.14) 44 5.28 ± 0.179 (4.95–5.62) 35 5.86 ± 0.195 (5.21–6.15) 41 M2 to M2 labial width 5.79 ± 0.194 (5.42–6.26) 44 6.9 ± 0.251 (6.38–7.37) 44 6.32 ± 0.182 (5.93–6.69) 35 6.78 ± 0.181 (6.45–7.1) 41 Palatal width 2.46 ± 0.123 (2.2–2.75) 44 2.68 ± 0.125 (2.44–3.03) 44 2.58 ± 0.1 (2.4–2.84) 35 2.69 ± 0.138 (2.42–2.96) 41 a The sample mean ± one standard deviation, the observed range in parentheses, and the sample size. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 35 (fig. 14D). In some specimens, the 1st and 4th interdigital pads are also pigmented around the base. The palmar surface is entirely pinkish white. The claws are translucent. The tail is subtly bicolored, with a brown dorsum and pale brown venter. Tiny applied hairs are present along the entire length of the tail, but they are barely visible to the naked eye along most of the length of the tail (fig. 14D). These hairs are slightly longer and white near the tip of the tail, creating a very small distal white tuft. In a minority of specimens, the integument is also white for the distal ≤20 mm of the tail. The tail bristles that are common at the base of the tail of many Crocidura are nearly absent in this species (fig. 14D). The skull is somewhat long and slender, with a tapering interorbital region, and moderately robust dentition (fig. 18B). The braincase is dorsoventrally inflated and bulges outward in the parietal region as compared with the more posterior interparietal. Relative to skull length the rostrum is quite short (fig. 10). The braincase is somewhat narrow relative to skull length, but the interorbital region is wide (fig. 10). Comparisons: This species is readily distinguished by its ratio of tail length to head-and-body length (fig. 9; table 2) from all Crocidura species on Sulawesi except other members of the Long-Tailed Group. Within the Long-Tailed Group, C. caudipilosa is smaller and has a much hairier tail, shorter hind foot, paler pelage, and lower relative interorbital width (IOW/CIL) but greater relative braincase breadth (BB/CIL) (figs. 9, 10). Within the Elongata Subgroup, C. microelongata has a smaller body size, shorter tail, shorter and slightly darker hind feet, and shorter skull than C. elongata and C. quasielongata (fig. 12; table 5). The thenar pad on the hind foot is shorter than in C. elongata, but comparable to that of C. quasielongta (fig. 14). Although the skull is shorter, its breadth is similar to that of the other two species, whether measured at the braincase, interorbital area, or rostral region (figs. 10, 12). The interorbital region, however, is more tapered than in either of the two most similar species (fig. 18). The dentition of C. microelongata is slightly smaller in proportion to the skull than in either C. elongata or C. quasielongata (fig. 18). Comments: Although we have not examined the specimens Ruedi (1995) identified as Crocidura elongata from Mt. Rorekatimbo (IZEA 4365 and 4396), a published cytochrome b sequence from IZEA 4396 is indistinguishable from mitochondrial sequences we obtained from Mt. Rorekatimbo samples of C. microelongata. Our mitochondrial gene trees placed C. microelongata as either sister to the other 19 species that make up Sulawesi’s endemic radiation (all species except C. nigripes) or to all members of the endemic radiation except C. musseri. However, statistical support for these hypotheses was nonexistent (fig. 4) or modest (fig. 5). Our analyses of nuclear DNA placed C. microelongata as part of the basal comb with no clear sister relationship (figs. 7, 8; supplementary data S6). See the next account for results of nuclear DNA species delimitation analyses. Specimens examined: Mt. Gandang Dewata (MZB 34736–34741, 34743–34745, 34748, 34749, 34751, 34753, 34755–34757, 38463, 38472, 38473; FMNH 218544–218547, 218584, 218593– 218603, 218969, 218972; NMV Z21764), Mt. Latimojong (MZB 40935, 40937, 40938, 43000; FMNH 212990–213005; MVZ 237567, 237569– 237572, 237594, 238121; NMV C38534), Mt. Rorekatimbo (FMNH 213146–213162, 213164– 213173, 213435, 213436), Mt. Torompupu (MZB 43013, 43014; NMV C40139). Crocidura quasielongata, new species LSID: urn:lsid:zoobank. org:act:551F4F6E-2983-4C71-923A047FB0E24B74 Crocidura “pale elongata” Esselstyn et al., 2019: 1715. Informal name. Holotype: MZB 43001 (= LSUMZ 36939), an adult male, collected on 15 March 2013 by J.L. Patton. The specimen was prepared as a study skin, cleaned skull and skeleton, and frozen tissues. External measurements from the holotype are 215 mm × 126 mm × 22 mm × 11 mm = 16 g. The voucher specimen and a tissue sample will be 36 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 permanently curated at MZB, with another tissue sample retained at LSUMZ. Type locality: Indonesia, Sulawesi Tengah, Toli Toli, Mt. Dako; 1.10998° N, 120.90339° E, 410 m. Etymology: We combine “quasi” with “elongata” because this species resembles C. elongata. Geographic distribution: Widespread on Sulawesi and recorded from all areas of endemism except the north-central and north-east (fig. 16). Populations identified here are from the westcentral (Wasponda and Mts. Balease and Torompupu, Central Sulawesi Province; Salu Tiwo of Mt. Gandang Dewata, West Sulawesi Province; Mt. Latimojong, South Sulawesi Province), south-west (Mt. Bawakaraeng, South Sulawesi Province), south-east (Mt. Mekongga, Southeast Sulawesi Province), east-central (Mts. Katopasa and Tompotika, Central Sulawesi Province), and northwest (Mt. Dako, Central Sulawesi Province) areas of endemism (fig. 16). We found this species from approximately 200 m at Salu Tiwo (low elevation Mt. Gandang Dewata site) to 1700 m on Mts. Mekongga and Katopasa and 1800 m on Mt. Bawakaraeng (fig. 13; table 3). Diagnosis: A long-bodied, somewhat heavily built, moderately bicolored shrew with a long tail and long, pale hind feet (table 2). The dorsal pelage ranges from gray-tan to gray-brown overall, with individual dorsal hairs having a gray base and tan to brown tip. Some specimens also have a narrow, tan band between the gray proximal section and brown tip of each hair. The ventral pelage has silver highlights, the visual effect of 120°E 1.5°N 0° 1.5°S 0–1000 m >2000 m 1000–2000 m 4.5°S 3°S 6°S 122°E 124°E 126°E 100 km Recent sample sites Miller and Hollister (1921) type localities C. elongata C. quasielongata C. microelongata FIG. 16. Map of Sulawesi showing localities sampled for shrews. Colored areas enclose localities with known records of members of the Elongata Subgroup. Although we excluded Pinedapa from the estimated geographic ranges, we suspect the two USNM specimens referred to Crocidura elongata by Miller and Hollister (1921) from this site represent C. microelongata. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 37 individual hairs each with a pale tip. In many specimens, the chest and throat area has a slight red tint due to variation in the color of the hair tips. The ears are large and pale. The mystacial vibrissae are dark proximally, but white distally, with the dark portion occupying 20%–80% of vibrissa length. The hind feet are long absolutely (table 2) and relative to head-and-body length (fig. 17). Dorsally, the feet range from entirely white, to brown at the ankle and wrist, slowly transitioning toward the white digits. Ventrally, the feet show the same transition (except in specimens where they are entirely white), but pigment is concentrated around the base of each foot pad. The claws are translucent (fig. 14B). The tail is subtly bicolored, with a brown dorsum and pale brown venter. Tiny applied hairs are present along the entire length of the tail, but they are barely visible to the naked eye along most of the tail. However, these hairs are slightly longer and white near the tip of the tail, creating a very small, sometimes white, distal tuft. Tail bristles are nearly absent (fig. 14B). The skull is long, primarily due to elongation of the postpalatal region, but not the rostral region (figs. 10, 18C). Relative to skull length, the braincase is especially narrow (BB/CIL) and the interorbital region somewhat narrow (IOW/CIL; fig. 10) and relatively untapered. The lambdoidal crest is prominent. The dentition is robust (fig. 18C). Comparisons: This species is easily distinguished by the ratio of tail length to head-andbody length (most specimens >110%; fig. 9) from all Crocidura species on Sulawesi except ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● N = 75 N = 56 N = 93 N = 112 N = 28 N = 96 N = 56 N = 44 N = 149 N = 4 N = 74 N = 94 N = 27 N = 17 N = 37 N = 51 N = 96 N = 33 N = 13 N = 8 N = 16 N = 74 N = 54 N = 92 N = 111 N = 26 N = 75 N = 58 N = 43 N = 155 N = 5 N = 72 N = 92 N = 18 N = 17 N = 34 N = 49 N = 96 N = 33 N = 14 N = 8 N = 16 RhoditisLong-Tailed Ordinary Small-Bodied Thick SPECIES MASS/HBL C. caudipilosa C. elongata C. microelongata C. quasielongata C. musseri C. nigripes C. normalis C. ordinaria C. solita C. australis C. pallida C. pseudorhoditis C. rhoditis C. baletei C. lea C. levicula C. mediocris C. parva C. tenebrosa C. brevicauda C. caudicrassa HF/HBL 0.15 0.20 0.25 0.30 0.05 0.10 0.15 0.20 FIG. 17. Box plots showing the length of the hind foot (HF) relative to the head-and-body length (HBL) and the ratio of mass to HBL. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. Species are ordered along the x-axis according to the species groups used in the text (Thick = Thick-Tailed Group). Lengths are in mm and mass is in grams. 38 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 other members of the Long-Tailed Group. Within this group, C. quasielongata is considerably larger, much stockier, has a much narrower relative braincase breadth (BB/CIL), and has a much less hairy tail than C. caudipilosa. Within the Elongata Subgroup, C. quasielongata is, on average, intermediate in size, tail length, and hind-foot length between the smaller C. microelongata and the slightly larger C. elongata (fig. 9; tables 2, 5). Crocidura quasielongata has long ears, second in length only to C. elongata (table 2). Although these measurements overlap between the species, the averages differ. On the hind foot, the thenar pad is shorter than in C. elongata (fig. 14), despite the similar hind-foot lengths shared by these species. Also, on average, C. quasielongata is paler than either C. elongata or C. microelongata, but there is substantial color variation across the range of the species. The pelage varies in overall color from tan to dark brown. The palest specimens of C. quasielongata are from Mt. Tompotika and Salu Tiwo of Mt. Gandang Dewata, while animals from Mt. Dako are slightly darker, and specimens from Mts. Balease, Katopasa, and Torompupu are darker still. These color differences may reflect a tendency for low-elevation animals to be paler than those sampled at higher elevations, perhaps an elevational version of Gloger’s Rule (Gloger, 1833). The palest specimens have a middle color band that is light gray on individual hairs. The skull of C. quasielongata is long, with a very narrow braincase and interorbital region. The interorbital region is also rather straight, barely tapering anteriorly. In this regard, the skull is very similar to, but slightly shorter than that of C. elongata, and it is much more elongate than in C. microelongata (fig. 12). In proportion to skull length, rostral length is greater, but postpalatal length is lesser in C. quasielongata than in C. elongata and C. microelongata (fig. 10). The dentition is slightly more robust than in C. microelongata but comparable to that of C. elongata (fig. 18). Comments: Although Crocidura microelongata is mostly separated in our PCA (fig. 11) and TABLE 6 Results of Principal Components Analysis of Craniodental Measurements of the Rhoditis Group of Crocidura Mt. Ambang All Sulawesi VariablesaComponent 1 Component 2 Component 1 Component 2 Condyloincisive length 0.6855 0.0425 0.6873 0.1399 Braincase breadth 0.2106 0.3206 0.2279 0.2567 Interorbital width 0.0683 0.1852 0.0988 0.2657 Rostral length 0.3426 -0.6866 0.3510 -0.4988 Postpalatal width 0.1140 0.0094 0.0830 0.0558 Rostral width 0.1050 0.3168 0.0881 0.1321 Postpalatal length 0.3406 0.2742 0.2633 0.4475 Condyle to glenoid fossa 0.2126 0.3072 0.1774 0.3981 Upper toothrow length 0.3146 -0.2646 0.3413 -0.3654 P4 to M3 length 0.1744 -0.1050 0.1960 -0.2046 M2 to M2 labial width 0.2104 0.1102 0.2473 -0.1987 Palatal width 0.0692 0.1625 0.1062 0.0320 Proportion of variance 0.8994 0.0281 0.8731 0.0336 Cumulative proportion 0.8994 0.9275 0.8731 0.9067 a Table entries for variables are component loadings. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 39 FIG. 18. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of the three members of the Elongata Subgroup: A, Crocidura elongata, LSUMZ 39259; B, C. microelongata, FMNH 213426; and C, C. quasielongata, LSUMZ 36939. 40 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 in univariate measures (fig. 12), C. elongata and C. quasielongata are much more difficult to distinguish, with average differences apparent only from large series of specimens identified with molecular data. Based on current sampling, geography can be a reliable predictor except that we found both species occurring on Mt. Dako and there remains a large sampling gap between Mt. Dako and the west-central area of endemism (i.e., the base of the northern peninsula; fig. 16). On Mt. Dako, we trapped C. elongata around 512 and 1600 m, whereas we captured C. quasielongata only around 410 m. We found C. quasielongata at higher elevations in other parts of the island and C. elongata at lower elevations at other localities (fig. 13; table 3). Thus, these two species may have a parapatric distribution partitioned by elevation on the one mountain where we found them together. Because these two species are so different morphologically from all the other species on the island, it would not be surprising if they fill similar functional niches and thus one excludes the other wherever they interact. Despite the morphological similarities of Elongata Subgroup members, genetic evidence is clear that these three species are distinct from each other and do not form a clade. None of our phylogenetic analyses (mtDNA, nuclear exons, or UCEs) even hinted at a sister relationship between any of the three species. Our mitochondrial inferences placed Crocidura quasielongata as sister to C. caudicrassa (figs. 4, 5), but this seems unlikely because C. caudicrassa is sister to the phenotypically similar C. brevicauda in UCE trees (figs. 7, 8). In our UCE species tree, C. quasielongata is sister to a mix of Ordinary Group and Rhoditis Group species (fig. 7). Despite these mixed signals, the lack of basal resolution among species in our phylogenetic estimates leaves the door open to possible sister relationships among Elongata Subgroup members. The similarities in cranial proportions (e.g., relative widths; fig. 10) between C. elongata and C. quasielongata suggest either inherited similarity, or remarkable convergence. If any of these three species ever show a sister relationship in future analyses, we suspect it will be this pair. FIG. 19. Bivariate plots showing the first two principal components from analyses of 12 cranial variables in the Rhoditis Group. Panel A shows analysis of individuals sampled syntopically on Mt. Ambang (C. pseudorhoditis and C. rhoditis) and panel B shows individuals sampled across the island. Loadings and variance explained by component axes are presented in table 6. -0.50 -0.25 0 0.25 0.50 -2 -1 0 1 2 3 COMP. 1 COMP. 2 -0.4 0 0.4 -2 0 2 COMP. 1 Species C. australis C. pallida C. pseudorhoditis C. rhoditis A B 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 47 intestine, and frozen tissues. External measurements from the type are 148 mm × 70 mm × 16 mm × 11 mm = 11 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with another tissue sample retained at LSUMZ. Type locality: Indonesia; Sulawesi Utara; Bolaang Mondgondow, Passi Timur; Insil; Mt. Ambang, near Lake Aliyah; 0.76385° N, 124.41188° E, 1481 m elevation. Etymology: We combine “pseudo” with “rhoditis” because this species looks very similar to C. rhoditis. Geographic distribution: We recorded this species from the northwestern portion of the west-central area of endemism (Mts. Torompupu and Rorekatimbo, Central Sulawesi Province), and the north-west and north-east areas of endemism of the northern peninsula (fig. 20; Mt. Dako, Central Sulawesi Province; Mt. Buliohuto, Gorontalo Province; and Mt. Ambang, North Sulawesi Province). The absence of records from the north-central area of endemism is almost certainly due to the lack of general mammal surveys and specimens from this region. Both specimens we report from Mt. Rorekatimbo were trapped by Ruedi (1995); we did not collect any Crocidura pseudorhoditis on Mt. Rorekatimbo, despite working at similar elevations. We found this species at a range of elevations (fig. 13), the low on Mt. Buliohuto (500 m) and the high on Mt. Rorekatimbo (2200 m; table 3). Diagnosis: Crocidura pseudorhoditis is a moderately large shrew (tables 2, 7) with a somewhat stocky build, medium gray, moderately bicolored pelage, a tail that is shorter than headand-body length, and dorsal foot surfaces that range from light gray-brown to pinkish white. The forefeet are paler than the hind feet and the claws are unpigmented and accompanied by a small tuft of white hairs on the hands, but on the hind feet, some of these hairs are dark. The tail is barely dorsoventrally bicolored proximally, but this transitions to a uniformly colored tail for the distal half of tail length. The tail has only sparse bristles over the proximal half of its length (fig. 21C). The lips are gray-brown, but the nose is distinctly paler. The palmar surface ranges from gray-brown to white, being palest on the digits. The color of the plantar surface also transitions from darker to paler colors toward the digits (fig. 21C), but all aspects are darker than on the forefeet. The skull is long (table 7) and broader at the braincase and interorbital region than expected given its length (figs. 10, 22B). The rostrum is long relative to the postpalatal portion of skull length, reflected in the RL/CIL (fig. 10). The suture between the squamosal and parietal bones is often open and in the shape of a sickle blade just below the opening of the sinus canal (fig. 22B). The maxillary bridge is wide. Comparisons: Crocidura pseudorhoditis is smaller than C. rhoditis, C. elongata, and C. quasielongata, but larger than C. caudipilosa, Rhoditis Group members C. australis and C. pallida, all members of the Small-Bodied Group, and all members of the Ordinary Group except C. nigripes, which is similarly sized (fig. 19; tables 2, 7). The body of C. pseudorhoditis is more robust than those of C. microelongata, C. australis, and C. pallida, but less stocky than in C. rhoditis and C. caudicrassa (fig. 17). Crocidura pseudorhoditis is slightly darker (both pelage and feet) than C. rhoditis and tail bristles, though not abundant, are still more prevalent than in C. rhoditis (fig. 21). The thenar and hypothenar pads on the hind foot are both more rounded than the oblong pads of C. rhoditis (fig. 21). Crocidura pseudorhoditis is similar in pelage color to C. australis and C. pallida. Braincase breadth relative to skull length is greater than in many of the species with somewhat similar body sizes, including C. rhoditis, and all Elongata Subgroup and Thick-Tailed Group species. However, C. pallida is comparable in this regard, and C. australis has an even greater relative skull breadth no matter where it is measured (fig. 10). The braincase is a bit more angular in C. pseudorhoditis than in C. rhoditis, with the widest part of the cranium in C. pseudorhoditis forming an obtuse point (fig. 22). However, the angularity of the braincase does not reach the degree seen in 48 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 C. nigripes. The ratio of rostral length to skull length is large in C. pseudorhoditis and exceeded only by that of C. rhoditis; the other Rhoditis Group members have comparatively short relative rostral lengths (RL/CIL) and outside the Rhoditis Group, C. nigripes and the two ThickTailed species (defined below) are comparable (fig. 10). Crocidura pseudorhoditis is larger in head-and-body length, foot length, and all cranial dimensions than C. australis and C. pallida (fig. 19; tables 2, 7). The slight difference in size between C. pseudorhoditis and C. rhoditis appears to be enhanced where the two species cooccur (Mt. Ambang; fig. 20), especially condyloincisive length (fig. 23). A principal components analysis of 12 cranial measurements that only included these two species readily separated them on the first axis, which represents size (fig. 19; table 6). Comments: While Crocidura pseudorhoditis is on average smaller than C. rhoditis, the two species are easily confused phenotypically and they occur in sympatry in the north-east area of endemism (fig. 20; table 3). The large mitochondrial distances between C. rhoditis and C. pseudorhoditis, along with the slight but consistent differences in size, which appear to be enhanced where they are syntopic (fig. 23), strongly suggest these are independently evolving populations. Our BPP analyses tested species limits with an alignment that contains 15 C. rhoditis and 58 C. pseudorhoditis and is 96% complete. The analyses supported these species’ distinction with 1.0 posterior probability with all prior combinations in all runs. One of the few cases of clarity from our phylogenetic analyses is the consistent and well-supported sister relationship between Crocidura rhoditis and C. pseudorhoditis (figs. 4, 5, 7, 8; supplementary data S6). Given their phenotypic similarity, this makes sense from a morphological perspective. In our UCE species tree, we found these two species sister to C. elongata (fig. 7). Specimens examined: Mt. Ambang (LSUMZ 39030, 39031, 39034–39036, 39039–39043, 39045, 39048, 39049, 39051, 39052, 39056, 39059, 39060, 39063, 39066, 39067, 39278, 39280–39283, 39293, 39297, 39298, 39300– 39309, 39311–39314, 39316, 39317, 39322; MZB 43002; NMV C37985, C37992, C37996, C38017), Mt. Buliohuto (LSUMZ 38275–38278, 38284; NMV C37793), Mt. Dako (LSUMZ 36973, 36978, 36979, 36986, 36990, 36991, 36993, 36995, 36998, 37000, 37002, 37005, 37007, 37008, 37011–37016, 37033, 37034; MZB 38564–38566; NMV C37252, C37254, C37264, C37268, C37292, C37297, 37308, 37315, C37328, 37329, C37363, C37367), Mt. Torompupu (NMV C40308), Mt. Rorekatimbo (RMNH 38409 (= IZEA 4406), IZEA 4407). Crocidura australis, new species LSID: urn:lsid:zoobank. org:act:3ABC433E-7C35-47DD-B52BD33CC37F8F62 Holotype: MZB 43003 (= MVZ 237610), an adult of unknown sex collected by K.C. Rowe on 30 October 2016. The specimen was preserved as a study skin, cleaned skull (fig. 24) and skeleton, and frozen tissues. External measurements from the holotype are: 141 mm × 65 mm × 16 mm × 11 mm = 9.8 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with another tissue sample retained at MVZ. Type locality: Indonesia, Sulawesi Selatan, Sinjai, Sinjai Barat, Gunung Perak Village, Mt. Bawakaraeng; 5.308463° S, 119.948661° E, 2390– 2550 m elevation. Etymology: We use the Latin for “southern,” as this species is the most southern member of the Rhoditis Group. Geographic distribution: This species is known only from the south-west area of endemism and was only collected from Mt. Bawakaraeng, South Sulawesi Province (fig. 20) on traplines placed around 1660–2040 and 2390– 2550 m elevation (fig. 13; table 3). Diagnosis: Crocidura australis is a mediumsized shrew (tables 2, 7) with a thick, mediumbrown dorsal pelage and slightly paler venter. Hairs of the middorsum are 6–7 mm long. The color of the tail matches that of the dorsal pelage, 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 49 but the feet are paler than the surrounding fur, particularly on the digits (fig. 21A). The tail is slightly shorter than the head-and-body length and not distinctly bicolored. Applied hairs on the tail are inconspicuous and bristles are sparsely distributed along the proximal half of tail length. The claws are translucent and surrounded by small tufts of white hairs. On the hind foot, the claws are long and the tufts more prominent than on the forefoot. The foot pads are more darkly pigmented than the surrounding plantar and palmar surfaces, but the difference is greater on the hind foot than on the forefoot. The external ears, though not small, are indistinct from the surrounding fur, due to the matching color, length, and density of the pelage. The mystacial vibrissae are relatively short, and mostly unpigmented. A few pigmented vibrissae are found posterior to the shorter, unpigmented vibrissae. Those with pigment are pigmented only proximally, typically for no more than half of their length. The braincase is wide relative to skull length (fig. 10), high, and somewhat angular, with a lateral point in the mastoid region and relatively prominent lambdoidal ridges (fig. 24A). The ridge formed by the parietal-squamosal suture is indistinct. The interorbital region is also wide relative to skull length (fig. 10), but it is strongly tapered. Despite the strongly tapered interorbital region, the maxillary process is not prominent when viewed from the dorsal aspect. The dentition is somewhat prominent relative to palatal width (fig. 24A). Comparisons: Crocidura australis is substantially larger in body size than all members of the Small-Bodied Group and somewhat larger than C. musseri, C. ordinaria, and C. solita of the Ordinary Group (fig. 9). It is smaller than members of the Thick-Tailed Group and Elongata Subgroup. Relative to members of the Rhoditis Group, it is smaller than C. rhoditis and C. pseudorhoditis in all dimensions except ear length, but similar in size to C. pallida (figs. 19, 23; tables 2, 7). In color, C. australis is darker than all other members of the Rhoditis Group, particularly on the feet. Crocidura ordinaria and C. solita of the Ordinary Group are similar in color and only a little smaller, but their braincases are more rounded than in C. australis. The somewhat angular shape of the braincase, however, is nevertheless more rounded than in C. pseudorhoditis. The great relative breadth of the braincase (BB/CIL) in C. australis distinguishes it from all other species except C. baletei (much smaller and darker), C. levicula (much smaller and darker), C. musseri (smaller and darker), and C. ordinaria (smaller). In comparison to other Rhoditis Group species, C. australis is substantially smaller in condyloincisive length and braincase breadth than the much larger skull of C. rhoditis and the somewhat larger skull of C. pseudorhoditis (fig. 19). Condyloincisive length is somewhat smaller than in C. pallida, although these two species are quite similar in head-and-body length. The interorbital region and labial breadth at M2 are also narrower than noted in C. rhoditis or C. pseudorhoditis (table 7). Relative rostral length (RL/ CIL) in C. australis is less than in any other member of the Rhoditis Group, though only slightly so compared to C. pallida. Comments: Published references to C. rhoditis from the southwestern peninsula (Musser, 1987; Ruedi, 1995) probably refer to this species. Crocidura australis was consistently inferred as sister to the clade containing C. ordinaria and C. solita of the Ordinary Group with varying degrees of support (figs. 4, 5, 7, 8; supplementary data 6). Specimens examined: Mt. Bawakaraeng (MZB 40991, 41027, 43003; NMV Z56801, NMV Z57200, NMV Z57223). Crocidura pallida, new species LSID: urn:lsid:zoobank. org:act:1249AC44-0D01-4060-B5FD3000D9C4D29D Holotype: MZB 43004 (= FMNH 210607), an adult female collected by J.A. Esselstyn on 18 October 2010. The specimen consists of a 50 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 dried skin, cleaned skull (fig. 24B) and skeleton, and tissue sample. It carried one embryo measuring 18 mm in crown-rump length. External measurements from the holotype are: 140 mm × 62 mm × 15 mm × 8 mm = 11 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with another tissue sample retained at FMNH. Type locality: Indonesia, Sulawesi Selatan, Luwu Utara, Sukamaju, Mt. Balease; 2.4995° S, 120.4874° E, 900 m elevation. Etymology: We use the Latin pallida to highlight the pale color of the feet of this species. Geographic distribution: Recorded from the west-central (Mt. Gandang Dewata, West Sulawesi Province; Mts.Torompupu and Balease, Central Sulawesi Province; Mt. Latimojong and Rindingallo, South Sulawesi Province), east-central (Mts. Katopasa and Tompotika, Central Sulawesi Province), and south-east areas of endemism (Mt. Mekongga, Southeast Sulawesi Province; fig. 20). FIG. 24. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of two members of the Rhoditis Group: A, Crocidura australis, MVZ 237610 and B, C. pallida, FMNH 210607. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 51 Across these areas, we found this species over a broad elevational range, from approximately 100 to over 2500 m (fig. 13; table 3). Diagnosis: Crocidura pallida is a moderately sized shrew (figs. 9, 23; tables 2, 7) with very pale feet (fig. 21B) and a somewhat pale ventral side of the tail. The tail is shorter than the head-andbody length (fig. 9; table 2). The dorsal pelage is gray to gray-brown while the ventral pelage is pale gray. The pinna and the dorsal side of the tail match the dorsal pelage, but the dorsal side of the feet are distinctly paler. The dorsal surface of the hand is nearly white, but some pigment is present near the wrist. The hind feet show a similar pattern but are modestly darker. Ventrally, the feet are also pale, especially on the digits, which are usually white. The darkest parts of the hind foot are usually the thenar and hypothenar pads (fig. 21B). The pads of the forefeet are rarely pigmented. Tail bristles are sparse to nearly absent (fig. 21B), extending along no more than the proximal third of the tail length. The tail varies from uniformly colored to moderately bicolored with a paler ventral side. The skull is typical of Crocidura of this size. The braincase is generally rounded, but a subtle lateral point is evident at the mastoid region when viewed from a dorsal aspect (fig. 24B). The braincase is somewhat inflated dorsoventrally, and it is wide relative to skull length (fig. 24B), as are the interorbital region and rostrum (fig. 10; table 7). The wide interorbital region gives the maxillary process a relatively weak appearance. In some individuals, the nasal passage is particularly inflated and laterally bulging, further obscuring the maxillary process. The rostrum is somewhat long, relative to skull length (fig. 10). The maxillary bridge is usually narrow, with an anteriorly placed lacrimal foramen. The posterior portion of the hard palate is narrow, sandwiched between broad molars. Comparisons: Crocidura pallida is smaller than C. rhoditis, C. pseudorhoditis, C. nigripes, and members of the Elongata Subgroup and Thick-Tailed Group. It is considerably larger than all members of the Small-Bodied Group and somewhat larger than all members the Ordinary Group except C. nigripes. In absolute terms and relative to head-and-body length, the tail length is comparable to members of the Ordinary, Thick-Tailed, and Rhoditis groups, but substantially shorter than in all members of the LongTailed Group and considerably longer than in any member of the Small-Bodied Group (fig. 9). Outside of the Rhoditis Group, most species have much darker feet than C. pallida. These include C. caudipilosa and C. microelongata of the Long-Tailed Group, C. normalis, C. musseri, and C. nigripes of the Ordinary Group, both Thick-Tailed Group members, and all members of the Small-Bodied Group except C. lea. Within the Rhoditis Group, C. pallida is smaller in absolute measurements (fig. 9) and more delicately built than C. rhoditis and C. pseudorhoditis (fig. 17); it is paler with a relatively narrower braincase and interorbital region than the otherwise similarly proportioned C. australis. Rostral length makes up a smaller proportion of skull length (RL/CIL) in C. pallida than in either C. rhoditis or C. pseudorhoditis, but this trait is comparable in C. australis (fig. 10). Comments: Substantial mitochondrial genetic divergence is evident between populations from Mt. Katopasa, Mt. Tompotika, and the remaining sites (up to 0.089 Jukes-Cantor distance; fig. 4; supplementary data S3). However, these populations form a cohesive set of morphological specimens, form a clade in our phylogenetic analyses of nuclear genes (figs. 7, 8; supplementary data S6), and all of the mitochondrial variation is partitioned geographically (i.e., no sympatry between divergent mitochondrial clades). We therefore did not divide them further. We identified a single specimen of Crocidura pallida from Mt. Latimojong (MVZ 237618), a locality where C. solita is abundant. Although C. pallida is slightly larger, these two can be difficult to distinguish. As such, it is possible that this specimen is a slightly large individual of C. solita with mtDNA introgressed from C. pallida. Unfortunately, we did not obtain nuclear loci (exons or UCEs) from this specimen and there- 52 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 fore cannot test for introgression. Contamination of this cytochrome b sequence is unlikely because it is unique in our alignment. We favor the hypothesis that MVZ 237618 is C. pallida because its cytochrome b sequence differs slightly from C. pallida sequences from nearby localities (i.e., Mts. Gandang Dewata and Balease) and phenotypically, it is nearer the averages for C. pallida than C. solita. Phylogenetic estimates were not consistent regarding the relationships of Crocidura pallida. Our mitochondrial gene trees put it as sister to a clade of Small-Bodied species, C. caudipilosa, and C. normalis (figs. 4, 5). However, our nuclearbased inferences placed C. pallida as part of the large basal polytomy (figs. 7, 8; supplementary data S6). Specimens examined: Mt. Balease (FMNH 210580–210592, 210608, 210609, MZB 43004), Mt. Gandang Dewata (FMNH 218687–218702, 218989; MZB 34872, 34886, 34888, 34889), Mt. Katopasa (LSUMZ 39527, 39529–39538; MVZ 238115–238118; NMV C40187, C40192, C40199, C40206, C40214, C40217, C40307, Z56723, Z62366, Z61754, Z62414), Mt. Latimojong (MVZ 237618), Mt. Mekongga (MWFB 8059, 8115, 8125, 8139, 8150, 8161, 8162, 8195, 8196, 8438, 8439), Rindingallo, Tana Toraja (MSB 93256), Mt. Tompotika (FMNH 213366–213369), Mt. Torompupu (NMV C40307). Small-Bodied Group We place the six smallest species into the Small-Bodied Group. All members have average head-and-body lengths between 61 and 65 mm and hind-foot lengths <13 mm (supplementary data S7). Two of these taxa, Crocidura lea and C. levicula, were described by Miller and Hollister (1921), while the remaining four species are new taxa described below. Three of the six species are endemic to portions of the northern peninsula. No phylogenetic analyses suggested all six species form a clade, but two probable sister relationships within this group do suggest a role for small-scale geographic isolation in speciation. Every locality we surveyed holds at least one member of this species group and three localities had two members, but no localities had more than two species (fig. 25). Bivariate plots of raw cranial measurements and results from a principal components analysis of cranial measurements show that these species largely, but incompletely, occupy distinct morphometric space (fig. 26). In this section, we first document the three species from the northern peninsula and then we diagnose taxa from the rest of the island. Crocidura lea Miller and Hollister, 1921 Crocidura lea Miller and Hollister, 1921: 102. Original description. Crocidura “pale lea” Esselstyn et al., 2019: 1715. Informal name. Holotype: USNM 217553, an adult male collected by H.C. Raven on 3 August 1916. Prepared as a skin and skull. External measurements from the holotype are 111 mm × 51 mm × 14 mm; ear length and weight were not recorded. Type locality: “Temboan, northeastern Celebes” (Miller and Hollister, 1921: 102; fig. 25). Temboan is located at 0.979° N, 124.605° E, 650 m elevation in the Southeast Minahasa Regency, North Sulawesi Province, 6 km south of Kalait. See the gazetteer (appendix) for details of our interpretation of Raven’s field notes. Geographic distribution: Probably endemic to the northern peninsula. We identified specimens of this species from the northwest area of endemism (Mt. Dako, Central Sulawesi Province and Mt. Buliohuto, Gorontalo Province) and the type locality is in the north-east area of endemism (Temboan, North Sulawesi Province). We did not find this species on Mt. Ambang (north-east area of endemism), where its ecological position is apparently held by another tiny, but not closely related shrew, Crocidura tenebrosa (fig. 25). We recorded C. lea at both high and low elevations on both Mts. Dako (512 and 1600 m) and Buliohuto (400– 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 53 600 and 1200 m; table 3). We did not collect any specimens of this species at our 410 m site on Mt. Dako. The type locality (Temboan) is at roughly 650 m. Emended Diagnosis: Crocidura lea is a very small shrew (tables 2, 8) with a brown dorsal pelage, gray-brown ventral pelage, and pale feet. The pinnae are prominent and slightly paler than the surrounding fur, especially at the lobe. The mystacial vibrissae are generally unpigmented, but a few, typically the longer ones, are brown or black proximally. Dorsally, foot color transitions from gray-brown at the wrist and ankle to pale pinkish white on the digits (fig. 27B). The claws are small, unpigmented, and sometimes lack the surrounding tuft of white hairs present in many other species. Ventrally, the forefeet mostly lack pigment, but the hind feet are darker. In the hind feet, color transitions from brown posteriorly from the heel, and to a lesser extent laterally, to white at the digits. However, pigment is concentrated in the pads, particularly around the base of the thenar, hypothenar, and in some cases the 4th (lateralmost) interdigital pad (fig. 27B). The tail is shorter than head-and-body length, sometimes dorsoventrally bicolored, and thinly covered with very small, dark brown applied hairs. A few sparse bristles are present along the proximal three-fourths of the tail (fig. 27B). The skull is short, narrow, and somewhat rounded in overall shape (fig. 28B). Relative to body size, the skull is slightly longer than expected, and relative to skull length, the braincase (BB/CIL) is especially narrow, but the interorbital region is not unusual in its relative width (IOW/CIL; fig. 10). The maxillary process is weak (fig. 28B). The I3 FIG. 25. Map of Sulawesi showing localities sampled for shrews. Colored areas enclose localities with known records of members of the Small-Bodied Group of Sulawesi Crocidura. 120°E 1.5°N 0° 1.5°S 0–1000 m >2000 m 1000–2000 m 4.5°S 3°S 6°S 122°E 124°E 126°E 100 km Recent sample sites Miller and Hollister (1921) type localities C. lea C. baletei C. tenebrosa C. levicula C. mediocris C. parva 54 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 (U2) is smaller than the C (U3). The parastyle of P4 is modest. Comparisons: Crocidura lea is much smaller than all Sulawesi Crocidura outside of the SmallBodied Group (fig. 9). Among the Small-Bodied species, only C. baletei and C. tenebrosa are known from the northern peninsula. Crocidura levicula, C. parva, and C. mediocris are apparently restricted to the central core and eastern and southwestern peninsulas (fig. 25). We therefore focus our comparisons on the cooccurring, northern peninsula species. However, first we note that the allopatric C. levicula has a broader skull (figs. 10, 26; tables 8, 9), shorter tail, shorter hind feet, and more tail bristles than does C. lea (figs. 27, 29; table 2). Among the Small-Bodied shrews of the northern peninsula, C. lea has a slightly paler and more strongly dorsoventrally bicolored pelage than C. baletei or C. tenebrosa. Both of the latter species are relatively uniform in color, C. baletei being medium brown and C. tenebrosa dark brown. Crocidura lea also has paler skin wherever it is exposed than either C. baletei (somewhat darker) or C. tenebrosa (much darker). Dorsally, the feet of both C. baletei and C. tenebrosa are uniformly dark, whereas the foot color transitions posteriorly from brown at the heel to white or pink at the digits in C. lea (fig. 27). Similarly, the tails of both C. baletei and C. tenebrosa are not obviously bicolored, and both are darker. Tail bristles are present on approximately three-fourths of the tail length in all three species, but they are much more abundant and longer on the tails of C. baletei and C. tenebrosa than in C. lea (fig. 27). Applied hairs on the tail are also much more visible in the two new species than in C. lea. Tail length in C. lea is greater, on average, than in C. baletei, and substantially so compared to C. tenebrosa (fig. 9; table 2). The skulls of C. lea are comparable in length, but significantly narrower at the braincase, interorbital region, maxillary process, and to a lesser extent at the rostrum than those of C. baletei and C. tenebrosa (figs. 10, 30; table 8). Crocidura lea occupies distinct morphometric space from the other northern peninsula endemics in bivariate plots of skull length and width and the first two principal components from an analysis of 12 cra7.5 8 8.5 16 17 18 CONDYLOINCISIVE LENGTH BRAINCASE BREADTH -0.5 0 0.5 -2 -1 0 1 2 COMP. 1 COMP. 2 Species C. baletei C. lea C. levicula C. mediocris C. parva C. tenebrosa A B FIG. 26. Bivariate plots showing A, variation in the condyloincisive length and braincase breadth and B, the first two axes from a principal components analysis of 12 cranial measurements among all members of the Small-Bodied Group. Loadings and variance explained are given in table 9. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 55 FIG. 27. Images showing the ventral surface of the hind foot and dorsal surfaces of the tail base (approximately 1 cm from rump) and tail tip from the three members of the Small-Bodied Group that are from the northern peninsula: A, Crocidura baletei, LSUMZ 36959 (right hind foot); B, C. lea, LSUMZ 38254 (left hind foot); and C, C. tenebrosa, LSUMZ 39268 (right hind foot). Scale bars represent 5 mm. Within each panel, the upper bar applies to the foot and the lower bar corresponds to both tail images. 56 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 nial measurements (fig. 26). The C (U3) is larger than I3 (U2) in C. lea, but they are usually subequal in occlusal surface area in C. baletei and C. tenebrosa. The parastyle of P4 is more prominent in C. tenebrosa than in C. lea or C. baletei. Comments: An 1111 bp cytochrome b sequence from the holotype (USNM 217553) provides strong evidence that the tiny shrews we collected on Mts. Buliohuto and Dako (samples from Mt. Dako were referred to as “Crocidura pale lea” by Esselstyn et al., 2019) represent this species. Interestingly, we did not find C. lea on Mt. Ambang, our sample site nearest the type locality. Rather, the tiny shrews we collected from Mt. Ambang represent an undescribed species (C. tenebrosa) that does not appear to be a close relative of C. lea. We suspect that C. lea is widespread at relatively low elevations on the northern peninsula, but is displaced by smallerrange, darker-colored endemics in some higherelevation areas (fig. 13; table 3). Our only surveys on Mt. Ambang were centered on 1500 m elevation (fig. 3). For BPP species delimitation results, see the C. tenebrosa account below. Ruedi (1995) reported Crocidura lea from Mt. Rorekatimbo, but we refer those specimens to C. normalis (see below) based on a cytochrome b sequence from Ruedi et al. (1998). None of our phylogenetic estimates found strong support for the closest relative(s) of CrocTABLE 8 Descriptive Statisticsa for Craniodental Measurements (mm) for Species of the Small-Bodied Group of Sulawesi Crocidura C. baletei C. lea C. levicula C. mediocris C. parva C. tenebrosa Condyloincisive length 17.68 ± 0.285 (17.25–18.07) 7 17.54 ± 0.293 (17.09–18.02) 21 16.58 ± 0.545 (15.56–17.58) 19 17.31 ± 0.643 (16.11–18.54) 25 16.55 ± 0.372 (15.81–17.34) 26 17.66 ± 0.216 (17.37–17.98) 8 Braincase breadth 8.46 ± 0.152 (8.27–8.65) 7 7.71 ± 0.135 (7.49–7.98) 21 7.98 ± 0.287 (7.51–8.49) 19 7.85 ± 0.246 (7.45–8.34) 25 7.47 ± 0.145 (7.09–7.72) 26 8.36 ± 0.166 (8.09–8.56) 8 Interorbital width 4.08 ± 0.058 (3.98–4.15) 7 3.89 ± 0.123 (3.69–4.14) 21 3.88 ± 0.136 (3.71–4.11) 19 3.88 ± 0.125 (3.68–4.14) 25 3.73 ± 0.109 (3.42–3.89) 28 4.12 ± 0.104 (4.04–4.26) 8 Rostral length 7.05 ± 0.242 (6.78–7.49) 7 6.86 ± 0.208 (6.48–7.27) 22 6.48 ± 0.22 (6.05–6.92) 19 6.91 ± 0.396 (6.37–7.7) 25 6.48 ± 0.182 (6.08–6.86) 28 7.09 ± 0.136 (6.85–7.22) 8 Postpalatal width 3.19 ± 0.088 (3.0–3.26) 7 3.13 ± 0.10 (2.95–3.33) 21 3.01 ± 0.101 (2.86–3.22) 19 3.09 ± 0.106 (2.8–3.3) 25 2.96 ± 0.113 (2.67–3.18) 28 3.2 ± 0.077 (3.12–3.33) 8 Rostral width 2.41 ± 0.162 (2.17–2.61) 7 2.4 ± 0.146 (2.13–2.68) 21 2.28 ± 0.125 (2.07–2.53) 19 2.34 ± 0.169 (2.13–2.67) 25 2.32 ± 0.147 (2.09–2.63) 28 2.55 ± 0.117 (2.44–2.74) 8 Postpalatal length 8.01 ± 0.124 (7.79–8.14) 7 8.08 ± 0.15 (7.81–8.42) 21 7.56 ± 0.265 (7.05–8.1) 19 7.9 ± 0.255 (7.34–8.54) 25 7.62 ± 0.197 (7.12–7.95) 24 8.06 ± 0.13 (7.89–8.26) 8 Condyle to glenoid fossa 7.25 ± 0.156 (7.03–7.43) 7 7.21 ± 0.162 (7.01–7.56) 21 6.83 ± 0.211 (6.5–7.2) 19 7.06 ± 0.22 (6.5–7.45) 25 6.94 ± 0.151 (6.71–7.17) 26 7.24 ± 0.077 (7.11–7.35) 8 Upper toothrow length 7.67 ± 0.118 (7.49–7.82) 7 7.52 ± 0.235 (7.13–7.98) 22 7.15 ± 0.222 (6.73–7.62) 19 7.54 ± 0.369 (6.81–8.28) 25 7.07 ± 0.187 (6.7–7.45) 28 7.62 ± 0.178 (7.34–7.84) 8 P4 to M3 length 4.41 ± 0.077 (4.33–4.52) 7 4.23 ± 0.135 (3.98–4.56) 22 4.09 ± 0.132 (3.87–4.33) 19 4.24 ± 0.201 (3.85–4.58) 25 3.98 ± 0.121 (3.73–4.3) 28 4.36 ± 0.098 (4.23–4.52) 8 M2 to M2 labial width 5.22 ± 0.063 (5.14–5.32) 6 5.03 ± 0.165 (4.61–5.37) 22 4.83 ± 0.174 (4.56–5.23) 19 5.0 ± 0.224 (4.58–5.48) 25 4.66 ± 0.137 (4.41–4.92) 28 5.25 ± 0.128 (5.15–5.49) 8 Palatal width 2.14 ± 0.074 (2.04–2.24) 6 1.98 ± 0.115 (1.8–2.32) 22 2.02 ± 0.105 (1.78–2.24) 19 1.98 ± 0.068 (1.85–2.1) 25 1.89 ± 0.102 (1.73–2.11) 26 2.08 ± 0.115 (1.92–2.24) 8 a The sample mean ± one standard deviation, the observed range in parentheses, and the sample size. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 63 claws are pale, perhaps lightly pigmented, and surrounded by a small tuft of brown hairs (fig. 29A). The skull is small but broad, more so at the braincase than at the interorbital region (figs. 10, 31A). Relative to body size and skull breadth, the skull is quite short, particularly the rostrum (fig. 10). The C (U3) is equal to or larger in occlusal area than the I3 (U2). Comparisons: Crocidura levicula is one of the smallest shrew species on Sulawesi, only being comparable to other members of the Small-Bodied Group (fig. 9). It has a shorter relative tail length than any other shrew species on Sulawesi (fig. 9). Its hind-foot length is shorter than in all Sulawesi shrews except one other member of the Small-Bodied Group, C. parva (fig. 9; table 2). Crocidura levicula is also darker in color than both C. lea and C. baletei, but not C. tenebrosa. Absolute tail length is slightly less in C. levicula than in C. parva. Tail bristles are more abundant on specimens of C. levicula than in C. lea, C. tenebrosa, and C. parva. The skull of C. levicula is small, delicate, and broad at the braincase and to a lesser degree at the interorbital region (fig. 10). Its skull width relative to length is greater than in C. lea, C. parva, and C. mediocris, and to a lesser degree, greater compared to C. tenebrosa (fig. 26). Crocidura levicula has a lesser skull length and breadth than C. baletei (fig. 26), but these two species have similar relative skull widths (fig. 10). Samples of Crocidura levicula are nearly nonoverlapping with other members of the Small-Bodied Group in morphometric space in bivariate plots of skull length versus width and along the first two axes from a PCA of 12 cranial measurements (fig. 26). In C. levicula, the C (U3) is equal to or greater in occlusal surface area than is I3 (U2) (fig. 31), which is similar to the conformation in C. lea. Comments: Miller and Hollister (1921) named this species based solely on the holotype, and unfortunately, we failed to obtain DNA from this specimen. We followed the Tsai et al. (2020) phenol-chloroform extraction protocol and used two separate extractions. The addition of resalting the ethanol supernatants did not yield a quantity of DNA that could be detected with a Qubit 2.0 fluorometer using the dsDNA High Sensitivity Assay Kit (Thermo Fisher Scientific, Waltham, MA). As such, our identification of Crocidura levicula is based on the morphological similarity of the holotype to specimens we collected in areas nearest the type locality. One specimen (NMV Z63390) from Mt. Torompupu appears to have an introgressed mitochondrion from syntopic Crocidura ordinaria, a member of the Ordinary Group detailed below. Our identification of this specimen is based on morphology alone; we did not sequence any nuclear DNA from this specimen and therefore cannot test our introgression hypothesis. In our phylogenetic estimates, UCE data confidently placed Crocidura levicula as sister to C. caudipilosa (figs. 7, 8). However, our nuclearexon and mitochondrial inferences placed this species as a member of a clade of mostly SmallBodied species that also includes C. caudipilosa (fig. 5; supplementary data S6). Crocidura levicula was delimited by all BPP analyses. See the C. tenebrosa account above for details. Specimens examined: Mt. Katopasa (LSUMZ 39512–39516; NMV C40180, C40181, C40200, C40203, C40207, Z55557), Pinedapa (USNM 219450), Mt. Rorekatimbo (FMNH 213192, 213193, 213271), Tolala (FMNH 210576, 210577), Mt. Tompotika (FMNH 213343– 213365), Mt. Torompupu (LSUMZ 39446–39449; NMV C40292, C40294, C40306, C40311, Z63365), Wasponda (FMNH 210578, 210579). Crocidura mediocris, new species LSID: urn:lsid:zoobank. org:act:1587FDA2-B27F-47C4-95DFE44A1081CCA4 Holotype: MZB 43007 (= FMNH 210603), an adult female collected by J.A. Esselstyn on 22 October 2010. The specimen consists of a dried skin, cleaned skull and skeleton, and tissue samples. External measurements from the holotype 64 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 FIG. 31. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of the three members of the SmallBodied Group that are not from the northern peninsula: A, Crocidura levicula, FMNH 213362; B, C. mediocris, FMNH 210603; and C, C. parva, MVZ 237577. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 65 are: 102 mm × 41 mm × 11 mm × 7 mm = 3.7 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with an additional tissue sample retained by FMNH. Type locality: Indonesia, Sulawesi Selatan, Luwu Utara, Sukamaju, Mt. Balease; 2.50002° S, 120.48726° E, 862 m elevation. Etymology: Mediocris is Latin for “average,” applied in recognition that this is a species of shrew with no striking phenotypic traits worthy of hanging a descriptive name on. Geographic distribution: This species is found across the southern and western portions of the west-central area of endemism (Mts. Torompupu and Balease, Central Sulawesi Province; Salu Tiwo, West Sulawesi Province; and Mt. Latimojong, South Sulawesi Province) and in the south-east area of endemism (Mt. Mekongga, Southeast Sulawesi Province; fig. 25). We found this species from approximately 200 to 1900 m elevation (fig. 13). Although the species was present at Salu Tiwo (ca. 200 m), we did not find it at higher elevations on Mt. Gandang Dewata (table 3). Diagnosis: Crocidura mediocris is another small shrew (tables 2, 8), with a delicate build and dark gray to medium brown pelage that is only slightly paler on the venter. The tail is shorter than head-and-body length and moderately dorsoventrally bicolored. The feet are somewhat paler than the pelage, more so around the digits (fig. 29B). The pelage covers the body completely, but individual hairs are short (2–3 mm at middorsum). Mystacial vibrissae are short relative to body size, and unpigmented along most of their length. The tail is covered in moderately dense bristles along the proximal two-thirds of its length and a relatively high density of short, dark, applied hairs along its entire length (fig. 29B). The dorsal surfaces of the digits and, in some specimens, the feet are light brown. The plantar and palmar surfaces are generally dark, but the ventral sides of the digits are white (fig. 29B). As is typical, more pigment is present on the posterior and lateral portions of the palmar and plantar surfaces. The skull is small and delicate, with a relatively robust dentition (fig. 31B). The braincase is somewhat narrow and the interobital region is narrow relative to skull length (fig. 10). The maxillary process is modest and the maxillary bridge is narrow (fig. 31B). The lambdoidal ridge is prominent for such a small species. Comparisons: Crocidura mediocris is one of the smallest species on Sulawesi, easily distinguished on body size alone from all species outside the Small-Bodied Group (fig. 10). Crocidura normalis is the smallest member of the Ordinary Group and may be closely related to C. mediocris and C. parva, also of the Small-Bodied Group (figs. 5, 7). Compared to C. normalis, C. mediocris is smaller, paler colored, and has a shorter tail (fig. 10; table 2). Among the Small-Bodied species, C. mediocris has the shortest average head-and-body length. Its tail is also short, and relative tail length is comparable to C. baletei, greater than in C. levicula, C. tenebrosa, and C. parva, and only slightly less than in C. lea (fig. 9). In color, the feet of C. mediocris are darker than those of C. lea. Aside from the relative tail-length differences, C. mediocris is similar to C. levicula in overall proportions but differs in having a longer and slightly narrower skull (table 8), paler pelage and feet, more rounded hypothenar on the hind foot (fig. 29), and on average, fewer tail bristles. Crocidura mediocris is also paler than both C. tenebrosa (fig. 27C) and C. parva (fig. 29C). In cranial proportions, C. mediocris has a greater average condyloincisive length than C. levicula and C. parva, but is comparable in this regard to C. lea, C. baletei, and C. tenebrosa (table 8). The length of the rostrum, relative to skull length (RL/CIL), is greater on average than in C. lea, C. levicula, and C. parva (fig. 10). The relative breadth of the braincase (BB/ CIL) is greater than in C. lea and slightly more than in C. parva, but less than in the other SmallBodied species. In morphometric space, a bivariate plot of condyloincisive length versus braincase breadth shows that C. mediocris occupies a widthto-length ratio between the narrow C. lea and C. parva and the wide C. levicula, C. baletei, and C. tenebrosa (fig. 26A). A PCA of cranial dimensions shows that specimens of C. mediocris occupy 66 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 moderately distinct morphometric space, overlapping primarily with individuals of C. lea and C. parva (fig. 26A). Comments: Crocidura mediocris is closely related to C. parva. See the C. parva account for a discussion of phylogenetic relationships between these two phenotypically similar species. For coalescent species delimitation results, see the C. normalis (Ordinary Group) and C. parva accounts below. Specimens examined: Mt. Balease (FMNH 210563–210575, 210602, 210604–210606; MZB 43007), Mt. Gandang Dewata (FMNH 218617, 218619, 218620, 218622–218638, 218640– 218642, 218644–218649), Mt. Latimojong (MVZ 237574), Mt. Mekongga (MWFB 8092, 8104, 8121, 8131–8136, 8140–8142, 8144, 8145, 8148, 8149, 8152, 8153, 13508, 13510, 13513, 13514), Salu Tiwo (FMNH 218614–218616, 218618, 218621, 218639, 218643, 218650, 218651), Mt. Torompupu (LSUMZ 39452–39457, 39555; MVZ 238109–238114; NMV C40246, C40251, C40253, C40274, C40278, Z62199). Crocidura parva, new species LSID: urn:lsid:zoobank. org:act:8C7D230C-7F04-4FE0-98965921A8574315 Holotype: MZB 43008 (= MVZ 237577), an adult female collected on 18 October 2016 by H. Handika. The specimen is preserved as a study skin, cleaned skull (fig. 31C) and skeleton, and frozen tissues. External measurements recorded in the field from the type are: 101 mm × 41 mm × 2 mm × 7 mm = 3.9 g. Hind-foot length for the holotype was erroneously recorded as 2 mm; the true value is almost certainly 12 mm. The voucher specimen and a tissue sample will be permanently curated at MZB, while an additional tissue sample will be retained at MVZ. Type locality: Indonesia, Sulawesi Selatan, Sinjai, Sinjai Barat, Gunung Perak Village, Mt. Bawakaraeng; 5.286815° S, 119.961406° E, 1713– 1754 m elevation. Etymology: Parva is Latin (feminine) for “tiny,” used in recognition of the diminutive body size of this species. Geographic distribution: This animal was extremely abundant on Mt. Bawakaraeng of the south-west area of endemism (South Sulawesi Province; fig. 25). We did not encounter it anywhere else and it may be endemic to this region. All specimens were collected between 1700 and 2500 m elevation (table 3). Habitat destruction has eliminated lowand middle-elevation forests in South Sulawesi, which may have altered the natural elevational distribution of this species. Diagnosis: Crocidura parva is among the smallest shrews on Sulawesi and it has the narrowest average braincase breadth of any species on the island (tables 2, 8). For a shrew of its head-and-body length, it has a rather delicate build (fig. 17). Crocidura parva has a gray-brown to dark brown pelage, with a slightly grayer venter. The fur is not particularly dense, and individual hairs on the middorsum are only about 3 mm in length, despite all specimens coming from mid to high elevation. Overall, the color of the skin on the feet, ears, lips, and tail match that of the surrounding pelage. The mystacial vibrissae are short (most <10 mm) and pigmented proximally for no more than half of their length. The tail length is short absolutely, and less than head-and-body length (fig. 9; table 2). Tail bristles are relatively abundant and are present along about two-thirds of the proximal tail length (fig. 29C). The skull is short, but also quite narrow at the braincase, giving it an elongate and dorsoventrally compressed overall appearance. The lambdoidal ridge is indistinct. The width of the interorbital region is middling relative to skull length (fig. 10) and the maxillary process is not prominent. Rostral length forms a relatively small proportion of skull length (fig. 10). The molar row is crowded on the narrow palate (fig. 31C). On the upper cheek teeth, the metacone is unusually prominent relative to the protocone, particularly on P4. Comparisons: Crocidura parva is much smaller than all known Sulawesi shrews except 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 67 other members of the Small-Bodied Group. Externally, C. parva is rather uniform in color, as are C. levicula, C. baletei, and C. tenebrosa, but other species have paler feet than bodies, including C. lea and to a lesser extent, C. mediocris. The overall color of C. parva is slightly darker than C. mediocris, and considerably darker than C. lea. The tail has more bristles than in C. mediocris, but fewer than C. levicula (fig. 29). The pelage is shorter than in other species, except that C. mediocris is similar. The skull of the tiny C. parva is slightly smaller overall than seen in any of the other very small taxa (table 8) and relative rostral length (RL/CIL) is less than in C. mediocris, C. baletei, and C. tenebrosa (fig. 10). Most distinctively, the braincases of the other species are more dorsoventrally inflated, particularly in the case of C. lea. The flat braincase of C. parva is narrower than in all other Small-Bodied species, but the range of values overlaps with those from C. lea, C. levicula, and C. mediocris (fig. 26). Bivariate plots of cranial length versus width and the first two axes from a PCA of 12 cranial dimensions show C. parva to occupy largely distinct morphometric space, but to overlap some with C. lea, C. levicula, and C. mediocris (fig. 26). Finally, in C. parva, on the upper molariform teeth, the protocone is relatively low, compared with those of the other Small-Bodied shrews (figs. 28, 31). Comments: We found this species only on Mt. Bawakaraeng, but our nearest sample sites are on Mt. Latimojong (fig. 25), some 215 km away. Much of the intervening habitat between Mts. Bawakaraeng and Latimojong is low elevation and dry, with the lowest area (the Tempe Depression) considered a barrier to many vertebrate taxa. Nevertheless, sampling additional sites in the south-west area of endemism may extend the known range of Crocidura parva. We interpret this probable isolation as additional support for distinguishing C. parva from C. mediocris, which is phenotypically similar. These two species are sister taxa in our mitogenome phylogeny (fig. 5), but each is paraphyletic with respect to the other in our UCE (figs. 7, 8) and nuclear exon phylogenies (supplementary data S6). Because of the slow evolutionary rate of UCEs and exons, we do not consider this to be strong evidence against their distinction. We tested species limits in BPP between Crocidura parva and C. mediocris and among C. parva, C. mediocris, and C. normalis. The former analysis employed 20 individuals of each species and the matrix is 95% complete. The second analysis used the same dataset, but with the addition of 36 specimens of C. normalis. This matrix is 94% complete. All analyses supported each species with a posterior probability of 1. Specimens examined: Mt. Bawakaraeng (MVZ 237575, 237576, 237578–237581, 237583, 237584, 237600–237609; MZB 43008; NMV Z57156, Z56280, Z56302, Z56314, Z56319, Z56995, Z57008, Z57012, Z57045, Z57046, Z57047, Z57057, Z57064, Z57103, Z57129, Z57208). Thick-Tailed Group We group two new species here that are more distinctive than most and are probably sister species. Both have somewhat large bodies (typically 80–90 mm head-and-body length), stocky body forms, and short, thick tails (50–75 mm in length; figs. 9, 17; table 2; supplementary data S7). Each species also appears to be a high-elevation endemic restricted to a single mountainous area. Principal components analyses show that these two species occupy distinct cranial morphometric space, but overlap almost completely in external morphometric space (fig. 32; tables 10, 11). Crocidura brevicauda, new species LSID: urn:lsid:zoobank. org:act:62AA5599-D510-4AAB-B5161D901C972A6E Holotype: MZB 43009 (= MVZ 237632), an adult female collected on 12 August 2016 by H. Handika, and prepared as a cleaned skull, forma- 68 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 lin-fixed carcass, and tissue samples. External measurements of the holotype are 130 mm × 56 mm × 15 mm × 9 mm = 12.0 g. The voucher specimen and a tissue sample will be permanently curated at MZB and an additional tissue will be retained at MVZ. Type locality: Indonesia, South Sulawesi Province, Luwu Regency, Latimojong District, Ulusalu, Gamaru Village, Mt. Latimojong; 3.43103° S, 120.09457° E, 2518 m elevation. Etymology: Brevicauda is Latin for “short tail,” indicating the relatively stubby tail that this species possesses. Geographic distribution: Only known from Mt. Latimojong of the west-central area of endemism (fig. 1), between 2300 and 2500 m elevation (fig. 13). The surveys we conducted on Mt. Latimojong during 2011 between 2000 and 2300 m did not find this species (table 3). Diagnosis: Crocidura brevicauda is a fairly large shrew (tables 2, 12) with a stocky build (fig. 17) and relatively short tail (fig. 9). The tail is somewhat thick and dark brown with many applied hairs. It has sparse, but long bristles along nearly its entire length (fig. 33A). The long dorsal fur (7–8 mm at middorsum) is gray-brown to dark brown, with a gray base and short brown tip. The fur coat is sufficiently thick and long that it somewhat obscures the ears. The hind feet are darker than the forefeet, the former being brown to dark brown dorsally, while the latter are pale brown. On all four feet, the thenar and hypothenar are less prominent than the four interdigital pads (fig. 33A). The skull width relative to length is midsized at the braincase and interorbital region (figs. 10, 34A). The rostrum is long relative to skull length (fig. 10). The lambdoidal ridge is prominent and the lateral margins of the braincase are somewhat angular, forming a dull point at the squamosal-parietal suture (fig. 34A). Comparisons: Crocidura brevicauda is considerably larger than all members of the Small-Bodied Group, larger than C. australis and C. pallida of the Rhoditis Group, has a much shorter tail than members of the Long-Tailed Group, is slightly smaller and has a narrower braincase than C. rhoditis and C. pseudorhoditis of the Rhoditis FIG. 32. Bivariate plots showing the results of principal components analyses of the two Thick-Tailed Group species using A, five external and B, 12 cranial measurements. Loadings and variance explained are given in tables 10 and 11, respectively. -4 0 4 -10 -5 0 5 10 COMP. 1 -0.4 -0.2 0 0.2 0.4 -1.0 -0.5 0.0 0.5 1.0 COMP. 1 COMP. 2 C. brevicauda C. caudicrassa A B 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 69 Group, is darker in color (pelage and feet) than all members of the Rhoditis Group, and is larger than all members of the Ordinary Group (detailed below) except C. nigripes. Crocidura nigripes, however, is usually very darkly colored, particularly on its feet, whereas C. brevicauda has pale brown to dark brown feet (fig. 33). Crocidura brevicauda also has a somewhat stockier body (fig. 17), much wider interorbital region (fig. 10), more rounded braincase, and a less robust dentition (fig. 34A) than C. nigripes. Crocidura brevicauda has a more luxuriant pelage than all other species except C. musseri and C. caudicrassa, the other member of the Thick-Tailed Group. Crocidura caudicrassa is generally similar to C. brevicauda, but can be distinguished by its even thicker fur, heavier body (fig. 17), longer skull, wider rostrum and braincase, and thicker tail (table 12). Comments: The extent of montane habitats on Mt. Latimojong is fairly limited and isolated from other such areas (fig. 1). As such, the geographic range of Crocidura brevicauda may be quite small. See the next account for details of phylogenetic relationships and coalescent species delimitation results. Specimens examined: Mt. Latimojong (MVZ 237568, 237597, 237616, 237629–237631, 237633; MZB 43009). Crocidura caudicrassa, new species LSID: urn:lsid:zoobank. org:act:8274BDB8-B7AF-46CC-A0A85EC15DC347D3 Holotype: MZB 34795, an adult female collected on 28 October 2011 by K.C. Rowe and preserved as a cleaned skull (fig. 34B), fluid-preserved body (fig. 33B), and tissue sample (NMV Z21760). External measurements are 144 mm × 62 mm × 17 mm × 10 mm = 16.5g. Type locality: Indonesia, West Sulawesi Province, Kabupaten Mamasa, Desa Tondok Bakaru, Kampung Rantepangko, Mt. Gandang Dewata, Post 3; 2.84534° S, 119.38216° E, 2580– 2640 m elevation. Etymology: Caudicrassa is Latin for “thick tail,” identifying this species’ most distinctive trait. Geographic distribution: Known only from the type locality around 2600 m on Mt. Gandang Dewata and from a single specimen collected by Luis Ruedas at 2120 m elevation from an area approximately 40 km ESE of Gandang Dewata in Rindingallo, of the west-central area of endemism (fig. 1; table 3). Diagnosis: A large (tables 2, 12), stocky shrew (fig. 17) with chocolate dorsal pelage (more reddish brown in MSB 93104 from Rindingallo), slightly grayer ventral pelage, and an unusually thick tail (fig. 33B). The dorsal hairs are dark gray at the base, with the overall pelage color determined by the browner approximately 1 mm tip. The tips of ventral hairs are a paler brown. The tail is shorter than head-and-body length (fig. 9) and holds conspicuous bristles spread along nearly its entire length (fig. 33B). The bristles are pigmented proximally for roughly half their length in the series from Mt. Gandang Dewata, but only for approximately 1 mm on the specimen from Rindingallo (MSB 93104). The tail varies from pale brown to dark brown dorsally and is slightly paler on the ventral surface. The overall color of the tail is largely determined by the many applied hairs that cover the tail scales. The feet are similar in color to the tail, dorsally and ventrally and both the tail and feet are slightly paler than the dorsal pelage. The feet are small relative to body mass, but not body length (fig. 17). The interdigital pads are exceptionally prominent, but the thenar and hypothenar are not unusual (fig. 33B). The pelage is unusually thick, with hairs at the middorsum approximately 8–10 mm long. The skull is large and robust, with a broad interorbital region (figs. 10, 34B). The rostrum is long relative to skull length (fig. 10; table 12). From a dorsal view, the braincase appears narrow, largely from the effect of the broad interorbital region. In dorsal view, the anteriorly converging lines formed by the sinus canal, interorbital margin, and rostrum above the maxillary process are quite straight. In ventral view, the rostrum is 70 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 narrow relative to the broad posterior palate. The molar row is robust (fig. 34B). Comparisons: Crocidura caudicrassa is larger (as estimated from skull length) than most other species of shrew on Sulawesi. The exceptions are C. elongata and C. quasielongata of the Elongata Subgroup, C. nigripes of the Ordinary Group, and C. rhoditis of the Rhoditis Group. Among these relatively large animals, C. caudicrassa is much stockier than C. nigripes and all members of the Long-Tailed Group (fig. 17; table 2). Only C. rhoditis has a body form nearly as robust, but it is substantially paler in pelage and skin color, particularly on the feet, and has a longer hind foot and thinner tail than C. caudicrassa (fig. 9; table 2). Crocidura caudicrassa could be confused with C. nigripes, despite its stockier body. However, C. caudicrassa differs by having a wider interorbital region relative to both braincase breadth and skull length and a less robust dentition than C. nigripes. Crocidura caudicrassa could also be mistaken for C. brevicauda, the only other member of the Thick-Tailed Group, but the latter has a less stocky body form, less prominent interdigital pads, shorter skull length, narrower rostrum and interorbital region, lesser braincase height, and less elongate interorbital region (table 12). The most distinctive feature of C. caudicrassa is its thick tail, which has no equal among Sulawesi’s Crocidura, but is approached by the somewhat thick tail of C. brevicauda (fig. 33). The pelage of C. caudicrassa is thick—only those of C. brevicauda and C. musseri, the latter of which is much smaller and does not have a particularly thick tail, are comparable. Comments: We tested species limits between the two Thick-Tailed species using BPP on a small dataset containing 13 Crocidura caudicrassa and two C. brevicauda. Twelve of the C. caudicrassa specimens lack three of the five loci in this alignment, and thus it is only 54% complete. Nevertheless, BPP delimited these two species with posterior probability of 1.0 in all replicates. The area around Mt. Gandang Dewata is an expansive region of montane habitat that is almost entirely unexplored by mammalogists. TABLE 10 Results of Principal Components Analysis of Craniodental Measurements of the Thick-Tailed Group of Crocidura Component 1 Component 2 Variablesa Condyloincisive length 0.6837 0.3462 Braincase breadth 0.2291 -0.3547 Interorbital width 0.1896 -0.2052 Rostral length 0.3488 -0.0117 Postpalatal width 0.1309 -0.1335 Rostral width 0.0266 0.0543 Postpalatal length 0.3080 0.3563 Condyle to glenoid fossa 0.2077 -0.0526 Upper toothrow length 0.2996 -0.0421 P4 to M3 length 0.1698 -0.1337 M2 to M2 labial width 0.1817 -0.5521 Palatal width 0.1223 -0.4870 Proportion of variance 0.7639 0.0682 Cumulative proportion 0.7639 0.8321 a Table entries for variables are component loadings. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 71 Although we describe Crocidura caudicrassa as a montane endemic, it may have a somewhat larger geographic range in this area. The single specimen from Rindingallo (~40 km from Mt. Gandang Dewata) hints at this possibility. We inferred a sister relationship between Crocidura caudicrassa and C. brevicauda in our analyses of UCEs (figs. 7, 8) and nuclear exons (supplementary data S6), but not in our analyses of mitochondrial DNA (figs. 4, 5). These two phenotypically similar species each appear to be montane endemics restricted to neighboring areas of high elevation, and thus we suspect that our UCE inferences reflect the correct relationship. Jukes-Cantor cytochrome b distances between these two species averaged 0.12, close to the mode of interspecific divergences among Sulawesi shrews and more than twice the median of intraspecific differences (fig. 6; supplementary data S4). Their morphological differences and presumed isolation by lowland habitats between Mts. Gandang Dewata and Latimojong further support their distinction. Specimens examined: Mt Gandang Dewata (MZB 34792–34798, 34801–34805), Rindingallo, Tana Toraja (MSB 93104). Ordinary Group We place five species that have medium body sizes, typical tail proportions (thickness and length), and integuments that are not especially pale in the Ordinary Group. The group includes Crocidura musseri, C. nigripes, and three new species. Crocidura nigripes is a distant relative of all other Sulawesi shrews (fig. 7), but the remaining four species also do not form a clade in any of our phylogenetic analyses. However, two of the species in this group are sister taxa. The species of the Ordinary Group have head-and-body lengths generally between 65 and 85 mm, average tail lengths range from 50 to 65 mm, and hind-foot lengths nearly always fall between 12 and 16 mm (supplementary data S7). These species vary considerably in color and pelage density. The animals grouped here are, with few exceptions, smaller than Long-Tailed, Rhoditis, and Thick-Tailed group species, while being larger than Small-Bodied Group members. A PCA of 12 cranial measurements for this group shows that C. nigripes and C. normalis occupy largely unique multivariate morphospace, but the three other species have extensive overlap on the first two axes (fig. 35; table 13). The two closely related taxa (C. ordinaria and C. solita) occur in sympatry where they possess deeply divergent mitochondrial haplotypes but are morphologically very similar. Crocidura nigripes Miller and Hollister, 1921 Crocidura nigripes Miller and Hollister, 1921: 101. Original description. TABLE 11 Results of Principal Components Analysis of External Measurements of the Thick-Tailed Group of Crocidura Component 1 Component 2 Variablesa Total 0.8975 0.4228 Tail 0.4113 -0.9001 Hind foot 0.0584 -0.0341 Ear 0.1018 -0.0962 Mass 0.1072 0.0238 Proportion of variance 0.6588 0.1931 Cumulative proportion 0.6588 0.8519 a Table entries for variables are component loadings. 72 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Crocidura nigripes lipara Miller and Hollister, 1921: 101. Original subspecies description. Holotype: USNM 217545, an adult male collected by H.C. Raven on 4 August 1916 and prepared as a skin and skull. External measurements from the holotype are 131 mm × 51 mm × 14 mm; ear length and weight were not recorded. Type locality: “Temboan (southwest from Tondano Lake), northeastern Celebes” (Miller and Hollister, 1921: 101; fig. 1). We estimate Temboan is in the Southeast Minahasa Regency of North Sulawesi Province, 6 km south of Kalait, at 0.979° N, 124.605° E, 650 m. See the gazetteer (appendix) for a full justification of our interpretation of Raven’s notes. Geographic distribution: Crocidura nigripes is generally regarded as a Sulawesi endemic that occurs broadly across lowland areas of the island (fig. 1), but the species was tentatively reported from Obi Island by Fabre et al. (2018). This latter record is based solely on the similarity of cytochrome b sequences between C. nigripes and a single specimen from Obi; we have not examined the Obi specimen. On Sulawesi, we recorded this species from the north-east (Mt. Ambang, Temboan, and Lembeh, North Sulawesi Province), north-central (Toraut, North Sulawesi Province), north-west (Mt. Buliohuto, Gorontalo Province and Mt. Dako, Central Sulawesi Province), west-central (Mts. Balease, Rorekatimbo, and Torompupu, Toare, Tolai, and Sungai Miu, Central Sulawesi Province; Mt. Gandang Dewata (including our lowland sample area at Salu Tiwo), West Sulawesi Province), and east-central areas of endemism (Mt. Katopasa and Peleng Island, Central Sulawesi Province). Notably, we did not record the species from the south-west or southeast areas of endemism. Similarly, Musser (1987) reported the species only from the west-central FIG. 33. Images showing the ventral surface of the hind foot and dorsal surfaces of the tail base (approximately 1 cm from rump) and tail tip from the two members of the Thick-Tailed Group: A, Crocidura brevicauda, MVZ 237632 (left hind foot); and B, C. caudicrassa, MZB 34795 (right hind foot). In B the upper scale bar applies to the foot and the lower to the tail. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 79 March 2011. The specimen was prepared as a study skin, cleaned skull (fig. 41A) and skeleton, and frozen tissues. External measurements from the holotype are: 124 mm × 55 mm × 13 mm × 8 mm = 4.9 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with an additional tissue sample retained at FMNH. Type locality: Indonesia, Sulawesi Tengah, Poso, Huasa, Sedoa, Lore Lindu National Park, Mt. Rorekatimbo; 1.2884° S, 120.3104° E, 2250 m. Etymology: Normalis is Latin for “normal,” used in recognition that this is yet another species of shrew with no striking phenotypic traits worthy of attaching a descriptive name. FIG. 37. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of two darkly pigmented members of the Ordinary Group: A, Crocidura musseri, FMNH 213255; and B, C. nigripes, FMNH 210611. 80 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Geographic distribution: We recorded this species at relatively high-elevation sites in Sulawesi’s west-central (Mt. Gandang Dewata, West Sulawesi Province; Mts. Latimojong and Rorekatimbo, Central Sulawesi Province), eastcentral (Mt. Katopasa, Central Sulawesi Province) and south-east areas of endemism (Mt. Mekongga, Southeast Sulawesi Province; figs. 13, 39). We found this species at sites ranging from 1400 to 2600 m (fig. 13, table 3). Diagnosis: Crocidura normalis is a mediumsized shrew (tables 2, 14), with a light build (fig. 17) and dark brown pelage, feet, lips, pinna, and tail. Dorsoventrally, the color is relatively uniform. The mystacial vibrissae are short relative to body length and darkly pigmented proximally for about half of their length. The tail can be as long as head-and-body length but is usually shorter (fig. 9). It is relatively densely covered with bristles, many of which are darkly pigmented from the base of the tail along approximately two-thirds of its length (fig. 40A). The small, applied hairs that typically cover the tail of Crocidura are less distinctly noticeable than in many other species. The feet are brown to black, usually uniformly so, including the digits and the thenar and hypothenar are subequal in area (fig. 40A). The claws are translucent. The skull is relatively gracile, being narrow across its entire length for a Crocidura of this size (fig. 10; table 14). Rostral length makes up a comparatively small proportion of skull length (fig. 10). The maxillary process is not prominent, the palate is narrow, and the occlusal surface area of the dentition is small relative to skull size (fig. 41A). The maxillary bridge is narrow. Comparisons: Crocidura normalis is smaller than all members of the Long-Tailed, ThickTailed, and Rhoditis groups, and larger than all members of the Small-Bodied Group. As the smallest member of the Ordinary Group, C. normalis is only slightly larger than C. mediocris (the FIG. 38. Bivariate plot of the first two principal components from an analysis of A, five external measurements and B, 12 cranial variables from across the geographic distribution of Crocidura nigripes on Sulawesi. Specimens coded as C. n. nigripes are those from the northern peninsula and specimens from all other areas were designated as C. n. lipara, per the designations of Miller and Hollister (1921) and Ruedi (1995). Loadings and variance explained are given in tables 15 and 16. -10 -5 0 5 -30 -20 -10 0 10 COMP.1 COMP. 2 C. n. lipara C. n. nigripes -0.6 -0.3 0 0.3 0.6 -2 -1 0 1 2 COMP.1 A B 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 81 largest member of the Small-Bodied Group). It differs from C. mediocris in having a darker, denser pelage (individual hairs approximately 5 mm at middorsum) and longer tail both absolutely and relative to HBL (fig. 9). Within the Ordinary Group, C. musseri has a wider braincase relative to skull length, more robust body (fig. 17), longer rostrum relative to skull length (fig. 10), and paler feet than C. normalis. Crocidura nigripes has a short tail, like that of C. normalis, but is substantially larger, usually has darker feet, and the skull of C. nigripes shows a more prominent dentition, longer rostrum, and narrower interorbital region relative to skull length (fig. 10). Crocidura ordinaria and C. solita are slightly larger than C. normalis, have longer tails, both absolutely and relative to HBL, have hypothenar pads larger than thenar pads, and have greater relative rostral lengths (RL/CIL), braincase breadths (BB/CIL), and interorbital widths (IOW/CIL) (fig. 10). Comments: In addition to the coalescent species delimitation analyses described above in the Crocidura parva account, we used BPP to test species limits between C. normalis and C. mediocris. The dataset consisted of 20 specimens of C. mediocris and 36 individuals of C. normalis. The sequence alignment is 93% complete. All replicates supported these species with 1.0 posterior probability. Unfortunately, we do not have nuclear exon data from the two specimens of C. normalis from Mt. Mekongga, which formed a clade independent of C. normalis from other localities in the cytochrome b and mitogenome gene trees (figs. 4, 5). In our UCE inferences, the Mekongga specimens of C. normalis are represented and the species is monophyletic in both our species tree and concatenated estimates (figs. 7, 8). If specimens from additional localities from the south-east and west-central areas of endemism are collected, reexamining these populations would be worthwhile. In both UCE estimates, C. normalis is a member of a clade comprising several Small-Bodied Group members and C. caudipilosa (figs. 7, 8). TABLE 15. Results of Principal Components Analysis of Craniodental Measurements of Crocidura nigripes Component 1 Component 2 Variablesa Condyloincisive length 0.7122 0.2664 Braincase breadth 0.2566 -0.4890 Interorbital width 0.1374 -0.2795 Rostral length 0.2880 0.2761 Postpalatal width 0.0902 -0.1729 Rostral width 0.0631 -0.1442 Postpalatal length 0.3172 -0.2060 Condyle to glenoid fossa 0.2488 -0.1090 Upper toothrow length 0.3039 0.2937 P4 to M3 length 0.1800 0.0828 M2 to M2 labial width 0.1518 -0.5245 Palatal width 0.0511 -0.2497 Proportion of variance 0.7867 0.0681 Cumulative proportion 0.7867 0.8548 a Table entries for variables are component loadings. 82 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Ruedi (1995) referred three specimens (IZEA 4393, 4394, 4042) to Crocidura lea and later Ruedi et al. (1998) sequenced a fragment of cytochrome b in one of these individuals (IZEA 4394). That sequence is identical to our C. normalis cytochrome b sequences from Mt. Rorekatimbo. Although we have not examined these three specimens, we presume they all represent C. normalis. Specimens examined: Mt. Gandang Dewata (MZB 34809, 34810, 34812, 34821; FMNH 218604–218613, 218652–218658, 218973– 218975), Mt. Katopasa (NMV Z61813), Mt. Latimojong (FMNH 213006–213008, 213010, 213011, 213013, 213014, 213030, 213032; MVZ 237595, 237622–237624), Mt. Mekongga (MWFB 8151, 8154), Mt. Rorekatimbo (FMNH 213174– 213189, 213257, 213438; MZB 43010). Crocidura ordinaria, new species LSID: urn:lsid:zoobank. org:act:62BBDEF5-DF9F-45B8-BA4F0CCDDB65B8AD Holotype: MZB 43011 (= FMNH 218726), an adult male, collected on 5 May 2012 by J.A. Esselstyn. The specimen comprises a skull (fig. 41B), formalin-fixed body, and frozen tissues. External measurements from the holotype are 142 mm × 65 mm × 16 mm × 10 mm = 11.0 g. The voucher specimen and a tissue sample will be permanently curated at MZB and an additional tissue sample will be retained at FMNH. Type locality: Indonesia, Sulawesi Barat, Mamasa, Mamasa, Tondok Bakaru, Rantepangko, Mt. Gandang Dewata; 2.8181° S, 119.3823° E, 2200 m elevation. Etymology: Ordinaria is Latin for “ordinary,” used in recognition that this is yet another species of shrew with no striking or unique phenotypic traits worthy of a descriptive name. Geographic distribution: Crocidura ordinaria is found in the west-central area of endemism (Mt. Gandang Dewata, West Sulawesi Province and Mt. Torompupu, Central Sulawesi Province) (fig. 39). The species spans an unusually broad elevational range from approximately 200 to 2600 m (fig. 13; table 3). Diagnosis: A moderately sized shrew (tables 2, 14) with a somewhat stocky build. The pelage is medium to dark gray-brown and thick, with hairs at the middorsum typically 6–7 mm long. The venter is paler, with hairs that are pale gray at the tip, but dark gray at the base. In some specimens, the tips of some ventral hairs are reddish brown, giving the belly and chest pale cinnamon highlights. The mystacial vibrissae are short and darkly pigmented for at least half their lengths. Dorsally, the feet are nearly as dark as the pelage, but some specimens have much paler TABLE 16 Results of Principal Components Analysis of External Measurements of Crocidura nigripes Component 1 Component 2 Variablesa Total 0.8466 0.4999 Tail 0.5281 -0.8149 Hind foot 0.0580 -0.0325 Ear 0.0135 0.1058 Mass 0.0277 0.2717 Proportion of variance 0.7943 0.1463 Cumulative proportion 0.7943 0.9406 a Table entries for variables are component loadings. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 83 digits (fig. 40B). The tail is shorter than head and body (fig. 9) and the abundance of tail bristles and applied hairs is variable. The skull of this species is typical in its length (relative to body size) for a Sulawesi shrew but is wide at the braincase and interorbital region relative to skull length (fig. 10; table 14). The braincase, though broad, is not especially inflated vertically. The dentition is more prominent than expected given the palatal width (fig. 41B), but, otherwise, the skull of Crocidura ordinaria is unremarkable. Comparisons: Crocidura ordinaria is a moderately sized member of the Ordinary Group. The tail is shorter than head-and-body length (fig. 9; table 2). Members of the LongTailed Group are larger and have much longer tails. Rhoditis Group members C. rhoditis and C. pseudorhoditis are larger. Crocidura pallida and C. australis, also members of the Rhoditis Group, are only slightly larger than C. ordinaria in head-and-body length. Compared to C. ordinaria, C. pallida has paler feet dorsally, a narrower relative braincase breadth (BB/CIL) and a narrower relative interorbital width (IOW/CIL) whereas C. australis has a narrower relative interorbital width, but wider relative braincase breadth than C. ordinaria (fig. 10). All members of the Small-Bodied Group are much smaller than C. ordinaria. Within the Ordinary Group, C. nigripes has darker feet and a relatively much narrower interorbital region and braincase than C. ordinaria. Compared to C. ordinaria, C. musseri has a thicker, darker pelage, and darker feet. Crocidura normalis is 120°E 1.5°N 0° 1.5°S 0–1000 m >2000 m 1000–2000 m 4.5°S 3°S 6°S 122°E 124°E 126°E 100 km Recent sample sites Miller and Hollister (1921) type localities C. musseri C. normalis C. ordinaria C. solita FIG. 39. Map of Sulawesi showing localities sampled for shrews. Colored areas enclose localities with known records of members of the Ordinary Group. To maintain clarity of presentation, the widespread Crocidura nigripes is not included. 84 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 FIG. 40. Images showing the ventral surface of the hind foot and dorsal surfaces of the tail base (approximately 1 cm from rump) and tail tip from three members of the Ordinary Group: A, Crocidura normalis, FMNH 213174 (left hind foot); B, C. ordinaria, FMNH 218726 (right hind foot); and C, C. solita, FMNH 213015 (left hind foot). Upper scale bar for foot, lower bar corresponds to both tail images. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 85 FIG. 41. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of three species belonging to the Ordinary Group: A, Crocidura normalis, FMNH 213457; B, C. ordinaria, FMNH 218726; and C, C. solita, FMNH 213044. 86 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 darker in color, smaller in body size, has more bristles on its darkly colored tail, and its skull is narrower with a shorter relative rostral length (RL/CIL) than C. ordinaria. Crocidura solita, another member of the Ordinary Group, is difficult to distinguish morphologically from C. ordinaria. External measurements are nearly identical between these two species (fig. 9), but C. ordinaria has a higher mass-to-length ratio (fig. 17). The pelage and feet of C. ordinaria are darker and have a smaller hypothenar (fig. 40), on average, than in C. solita. Cranially, C. ordinaria has a wider skull, observable in the absolute and relative breadths at the rostrum, interorbital region, and braincase (figs. 10, 42; table 14). Principal components analyses of external and cranial dimensions show that these two species overlap broadly in multivariate morphometric space, more so with external measurements than with cranial measurements (fig. 43; tables 17, 18). Comments: See extensive comments detailing our decision to distinguish this species from Crocidura solita in the next species account. Specimens examined: Mt. Gandang Dewata (FMNH 218727–218743, 218763–218767, 218769, 218771, 218772; MZB 34806, 34808, 34816, 34820, 34827, 34833, 34856, 34870, 34871, 34876, 34877, 34883, 43011; NMV Z21910, Z21911, Z21938), Salu Tiwo (FMNH 218744), Mt. Torompupu (LSUMZ 39480; NMV C40252, C40273). Crocidura solita, new species LSID: urn:lsid:zoobank. org:act:B8B27A48-E1C7-47F1-B0B8938722284C32 Holotype: MZB 43012 (= FMNH 213044), an adult male collected 1 March 2011 by J.A. Esselstyn. The specimen consists of a cleaned skull, fluid preserved body, and frozen tissue samples. External measurements from the holotype are 147 mm × 68 mm × 16 mm × 9 mm = 9.5 g. The voucher specimen with a tissue sample C. ordinaria C. solita SPECIES P4 TO M3 4.8 5.1 5.4 5.7 2.25 2.5 2.75 3 INTERORBITAL WIDTHROSTRAL WIDTH 4.25 4.5 5 4.75 N = 16 N = 43 N = 16 N = 43 N = 16 N = 43 FIG. 42. Box plots showing subtle differences in cranial measurements between Crocidura solita and C. ordinaria, two members of the Ordinary Group. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. All measurements in mm. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 87 will be permanently curated at MZB, with an additional tissue sample retained at FMNH. Type locality: Indonesia; Sulawesi Selatan; Enrekang; Buntu Bato; Latimojong Village; Karangan; Mt. Latimojong, Bantanase; 3.40755° S, 120.0078° E, 2050 m. Etymology: Solita is Latin for “usual,” used in recognition that this is another species of shrew with no striking phenotypic traits worthy of attaching a descriptive name. Geographic distribution: We recorded Crocidura solita on three mountains in the west-central area of endemism (Mts. Latimojong and Rorekatimbo, Central Sulawesi Province; and Mt. Gandang Dewata, West Sulawesi Province; fig. 39). Records of this species span a broad range of elevations, from 700 to 2600 m. On Mt. Gandang Dewata, C. solita occurred syntopically with its sister species, C. ordinaria, at middle and high elevations (around 1600 and 2600 m; fig. 13; table 3). Diagnosis: A medium-sized shrew (tables 2, 14) with a medium gray dorsal pelage and lighter gray ventral pelage. Tail length is slightly shorter than head-and-body length (fig. 9). The tail is only slightly bicolored, but some individuals have at least a few white applied hairs, giving it a somewhat silvery appearance, particularly near the tip. Dorsally, the feet are paler than the surrounding pelage, typically transitioning from light brown posteriorly to nearly white on the digits (fig. 40C). Ventrally, the feet are darker around the thenar and hypothenar pads than on the surrounding plantar and palmar surfaces; the hind feet tend to be darker than the forefeet. The external ears are slightly paler than the surrounding pelage. The mystacial vibrissae are short and mostly unpigmented, but a few of the longer, more posterior vibrissae are pigmented at their base. The skull is average in length (relative to HBL) for a Sulawesi shrew and slightly wide at the braincase and interorbital region relative to skull length (fig. 10). The braincase is rounded, but with a somewhat prominent lambdoidal crest (fig. 41C). The suture between the squamosal and parietal bones is often open, leaving a long slit below the sinus canal. The interorbital region is well tapered. The maxillary bridge is thin. FIG. 43. Bivariate plots showing the first two axes from principal components analyses of A, five external and B, 12 cranial measurements from Crocidura solita and C. ordinaria, two members of the Ordinary Group. Loadings and variance explained are given in tables 17 and 18, respectively. -5 0 5 10 -20 -10 0 10 20 30 COMP. 1 COMP. 2 -0.8 -0.4 0 0.4 -1 0 1 2 COMP. 1 C. ordinaria C. solita AB 88 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Comparisons: For comparisons to most species, see the Crocidura ordinaria comparisons section above. Compared to C. ordinaria, the pelage is less dense (i.e., shorter hairs on the dorsum) and both the pelage and feet are paler on average and the body is less stocky (fig. 17). The skull of C. solita is slightly smaller, and it is also narrower both absolutely and relative to skull length (figs. 10, 42), with a narrower palate and less robust dentition (table 14). The suture between the squamosal and parietal bones is often open, leaving a long slit in C. solita, but this suture is usually closed in C. ordinaria. Comments: We posit that Crocidura solita and C. ordinaria are phenotypically similar sister species. Morphologically, we note subtle differences of body size, relative skull widths, and coloration. In the absence of other evidence, these slight morphological differences would be too little to justify dividing these specimens into two species, and we would not have suspected multiple taxa were represented by these specimens if it were not for our use of mitochondrial sequences. Syntopic specimens of these two species from Mt. Gandang Dewata are separated by a mitochondrial Jukes-Cantor distance of 0.064 (0.087 when all specimens are used in the calculation) and specimens of each species from the zone of parapatry is more closely related in the mitochondrial gene tree to conspecifics from other parts of the island (figs. 4, 5; supplementary data S2–S5). The mitochondrial distance between syntopic individuals and closer relatedness to allopatric populations suggests that these phenotypically similar animals are most likely evolving independently of each other. In our mitochondrial gene trees, Crocidura ordinaria and C. solita are well-supported sister taxa and reciprocally monophyletic (figs. 4, 5). Our inferences using UCEs again indicate a close relationship with the two species forming a clade, but each species is reciprocally paraphyletic in our concatenated and species-tree inferences, the latter of which treated individuals as “species” and therefore did not force monophyly (figs. 7, 8). Our phylogenetic estimate from concatenated TABLE 17 Results of Principal Components Analysis of Craniodental Measurements of Crocidura ordinaria and C. solita Component 1 Component 2 Variablesa Condyloincisive length 0.6484 0.2373 Braincase breadth 0.2346 -0.4093 Interorbital width 0.1273 -0.3353 Rostral length 0.3585 0.3436 Postpalatal width 0.1031 -0.2452 Rostral width 0.0905 -0.5550 Postpalatal length 0.3174 -0.0198 Condyle to glenoid fossa 0.2210 -0.1585 Upper toothrow length 0.3387 0.2051 P4 to M3 length 0.1900 -0.0701 M2 to M2 labial width 0.2352 -0.3234 Palatal width 0.0730 -0.0226 Proportion of variance 0.7582 0.0779 Cumulative proportion 0.7582 0.8361 a Table entries for variables are component loadings. 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 95 ences in the extent to which animals climb trees and shrubs (Nations et al., 2019). The extremely long tails and hind feet of Elongata Subgroup members (fig. 9) must be significant to locomotory mode, but with few direct observations it is difficult to say how. Crocidura caudipilosa also has a relatively long tail, but its hind feet are shorter than in Elongata Subgroup members. Two specimens of C. caudipilosa have indeed been observed climbing, one of which was caught climbing a vertical tree trunk (Esselstyn et al., 2019). We are aware of few other observations of the locomotory habits of Sulawesi shrews; Musser (1982) reported capturing a shrew in a tree on Sulawesi, but it is unclear to what species he was referring. Furthermore, making predictions from morphology alone is tricky because trait values often overlap between locomotor modes in small mammals (Samuels and Van Valkenburgh, 2008; Nations et al., 2019). A long tail, for instance, is characteristic of both arboreal and saltatorial small mammals (Hickman, 1979), but the combination of a long tail and long hind feet may be better explained by saltation (Brosset, 1988). If Elongata Subgroup members are indeed hoppers, this may be related more directly to avoiding predators such as owls, than it is to how these animals forage. Perhaps the foraging habits of Elongata Subgroup members give them more exposure to aerial predators. Despite the uncertain ecology of these species, the largely parapatric geographical distribution of Elongata Subgroup members suggests that they each occupy similar ecological niches, though at different elevational ranges (figs. 13, 16), as noted by Eldridge et al. (2018). We found one or two members of this subgroup (not a clade in any of our phylogenetic analyses) on every mountain we surveyed. On all four mountains where we found two members, elevational distributions of the two species were either separate or abutting at a middle elevation (table 3). In general, the frequency of elevational parapatry between phenotypically similar species suggests that these morphological traits are reflective of ecological similarities that hinder coexistence. While it is fairly obvious that phenotypic differences indicate ecological differences, which in turn facilitate interspecific coexistence, we also found two phenotypically very similar sister species, Crocidura ordinaria and C. solita, occurring in syntopy on Mt. Gandang Dewata. The differences we observed in morphology between these two taxa are too slight to offer any clues as to how they might differ ecologically, assuming they do in fact differ. Of course, coexisting species such as these may differ in important physiological or behavioral traits that are not observable in their anatomy. Both species were abundant in the areas where we found them together (we identified 21 C. solita and 41 C. ordinaria from the zone of overlap; both species were found around 1600 and 2600 m, but we only caught C. ordinaria around 2200 m). With both species present at two widely separated elevational bands, we suspect their cooccurrence is more than an ephemeral interaction. We found a somewhat similar situation with the sister pair C. rhoditis and C. pseudorhoditis. Morphological differences in this species pair are more substantial, but individual specimens are still challenging to identify with morphology alone. Where C. rhoditis and C. pseudorhoditis occur together (Mt. Ambang), we observed slightly greater differences in their size-related morphological traits (fig. 23). This pattern is consistent with character displacement in body size in areas where phenotypically similar species are syntopic. Demos et al. (2017) found a similar phenomenon between C. umbra and C. monticola on Java, where these two close relatives were found occurring syntopically at middle elevations on Mt. Gede. We suspect that modest levels of character displacement, which is often noted in less speciesrich shrew communities (e.g., Malmquist, 1985), is common in Southeast Asian shrew communities, where similarly sized species have made secondary contact after a period of isolation. If our supposition is correct, the intraspecific geographic variation generated by character displacement in areas of range overlap would help explain why it can be so difficult to link allopatric populations of individual species using morphology alone. 96 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Regional geography of shrew diversity: The 21 species of Crocidura now known from Sulawesi dwarf the known shrew faunas of other islands. The major Sundaic islands that neighbor Sulawesi are somewhat smaller (Java) or considerably larger (Borneo and Sumatra) in land area and they all have higher mountains than Sulawesi (fig. 1A). In addition, these Sundaic islands were all connected to the mainland during glacial periods (Voris, 2000). Within the genus Crocidura, Borneo is known to have only three species, Sumatra eight, and Java seven (Esselstyn et al., 2014; Phillipps and Phillipps, 2016; Demos et al., 2017). However, recent discoveries of new species of Crocidura from Java (Esselstyn et al., 2014; Demos et al., 2017) and reports of undescribed species from Sumatra (Demos et al., 2016) suggest the Sundaic shrew fauna, as currently estimated (18 species excluding the Malay Peninsula), is also incompletely known (Hinckley et al., 2021). It is impossible to say whether these islands are likely to hold as many undescribed species as Sulawesi has until now, but Borneo’s known shrew diversity is oddly low for such a massive island with exceptional diversity in many other groups. Two other shrew genera are known from Borneo, but neither is diverse (one species of Chimarrogale and two of Suncus are native; Medway, 1965; Phillipps and Phillipps, 2016). Much of what is known of Borneo’s mammal fauna is based on surveys from Mt. Kinabalu and neighboring areas. This is by far the most mountainous portion of the island and will almost certainly hold the greatest small mammal diversity, but the island’s vast areas of lowland habitats are largely unsampled, and phylogeographic studies have commonly documented divergent lineages of various vertebrate taxa despite limited sampling (Gorog et al., 2004; Lim et al., 2017). We suspect that none of these islands’ shrew faunas are fully documented by the current taxonomy. In the Philippines, the shrew faunas of two oceanic islands (Luzon and Mindanao) that approach the land area of Sulawesi contain only one or two species each (Esselstyn and Brown, 2009; Esselstyn et al., 2011). However, Crocidura appears to have arrived in the oceanic portions of the Philippine archipelago more recently than they arrived in Sulawesi (Esselstyn et al., 2009), and this may explain much of the difference in diversity. If Sulawesi’s shrew diversity is indeed unusually rich, the most obvious geographical differences from other Southeast Asian islands are isolation from the mainland (Sulawesi is an oceanic island; Sundaland has only been intermittently isolated from the mainland during the Quaternary [Voris, 2000]), Sulawesi’s history as a complex of islands (the most recent island coalescent events occurred approximately 1–2 million years ago; Nugraha and Hall, 2018), and the island’s peculiar K-shape. Geographic isolation is known to be a common cause of speciation and radiation (MacArthur and Wilson, 1967), and peninsulas also lead to isolation by limiting potential paths of dispersal between suitable habitats (e.g., Giarla et al., 2018). These geographical factors may be especially effective at fostering radiation, but we have little prospect of understanding these forces until comprehensive biodiversity inventories and thorough taxonomic revisions have been completed for many taxa across the region. Within-island diversification processes: Explaining how Sulawesi’s remarkable shrew diversity arose requires a speciation mechanism that operates quickly (although there is considerable uncertainty, we suspect the crown age for Sulawesi’s endemic shrew radiation is <5 million years) and on a small spatial scale. We observed parapatric distributions among phenotypically similar taxa, an elevational influence on local community structure, and mitochondrial diversity largely consistent with species boundaries but also arising in some taxa with broad geographic distributions. Taken together, these observations suggest a speciation mechanism initiated by within-island geographic isolation and subsequently maintained upon secondary contact by some combination of competitive exclusion, character displacement, Bateson-Dobzansky-Muller incompatibilities (Bateson, 1909; 2021 ESSELSTYN ET AL.: SYSTEMATICS OF SULAWESI SHREWS 97 Dobzhansky, 1937; Muller, 1940; see below), or perhaps behavioral incompatibilities. The numerous elevational gradients on Sulawesi, with varying degrees of connectivity to neighboring mountains, provide ample opportunity for isolation of forest-adapted species. Climatic fluctuations through the Quaternary probably shifted the elevational distributions of various forest types (Whitmore, 1984; Whitten et al., 1987), and populations adapted to, for instance, montane forest would have experienced varying degrees of isolation over the last few million years. Pleistocene sea-level fluctuations and Sulawesi’s history as an archipelago prior to 1–2 million years ago (Nugraha and Hall, 2018) provided further opportunities for geographic isolation. Once a population had been isolated sufficiently long for genetic or behavioral incompatibilities to arise, gene flow would be hindered upon secondary contact and character displacement might alleviate resource competition. Mitochondria are functionally critical and evolve rapidly, accumulating mildly deleterious mutations that are compensated for by interacting nuclear genes (e.g., Chou and Leu, 2010; Hoekstra et al., 2013; Adrion et al., 2015). This process offers a plausible mechanism for initial genetic incompatibilities to arise quickly in temporarily allopatric populations (e.g., Patel et al., 2016; Hill, 2019; Tobler et al., 2019; Rank et al., 2020). Upon secondary contact, gene flow would be prevented by the functional mismatch between interacting mitochondrial and nuclear genes, a form of Bateson-Dobzansky-Muller incompatibility. The importance of mito-nuclear compatibility to organismal fitness has been demonstrated in a diversity of motile animal taxa, including fruit flies (Montooth et al., 2010; Patel et al., 2016), copepods (Barreto and Burton 2013a, 2013b), beetles (Rank et al., 2020), and mice (Ma et al., 2016), and compensatory evolution of nuclear genes that interact with mitochondria has been found in primates (Osada and Akashi, 2012). Shrews, with their high activity level and fast metabolism, may be especially dependent on high-functioning mitochondria and thus perhaps also especially susceptible to the consequences of mito-nuclear interactions. While this proposed model of diversification is entirely speculative, it is consistent with available data, and offers a logical mechanism for generating high levels of species diversity and endemism on a short evolutionary time scale in a small geographic setting. CONCLUSION Discoveries of new mammal species remain common globally (e.g., Ceballos and Ehrlich, 2009; Giam et al., 2010; Percequillo et al., 2011; Heaney et al., 2011; Li et al., 2019), but reports of more than a couple new species in a single paper are rare. Our discovery of 14 new species from a single endemic clade undoubtedly stems from multiple factors, including those that likely fostered shrew diversity in the first place and those that reflect the efforts of biologists, such as the paucity of historical biodiversity inventories undertaken on the island. Further exploration of the evolutionary history of Sulawesi’s shrew fauna may reveal fascinating details of the processes that produced such a rich radiation, but completing such studies will require continued dedication to growing the natural history collections that make ecological and evolutionary insights possible. ACKNOWLEDGMENTS This work would not have been possible without the many natural history museums that obtain and curate voucher specimens. In this work, we relied heavily on several institutions and their staff: American Museum of Natural History, United States National Museum of Natural History, Field Museum of Natural History, Louisiana State University Museum of Natural Science, University of California Museum of Vertebrate Zoology, Museums Victoria, Museum Zoologicum Bogoriense, Museum of Wildlife and Fish Biology, Museum of Southwestern Biology, Museum of Texas Tech University, Naturalis 98 BULLETIN AMERICAN MUSEUM OF NATURAL HISTORY NO. 454 Biodiversity Center, and the University of Kansas Biodiversity Institute. We are grateful to the Government of Indonesia for access to source material. The Indonesian Ministry of Research and Technology, Ministry of Environment and Forestry, and the local governments on Sulawesi provided permit and logistical support. Our work was supported by grants from the U.S. National Science Foundation (OISE-0965856, DEB-1343517, DEB-1441634, DEB-1457654, and DEB-1754393), National Geographic Society (9025-11, WW-160R-17), and the Alfred L. Gardner and Mark S. Hafner Mammalogy Fund at LSUMZ. The collections at MWFB that we used were supported by Grant #U01TW008160 from the Fogarty International Center, the Office of Dietary Supplements, the National Science Foundation, and the Department of Energy; the USDA Agricultural Food Research Initiative of the National Institute of Food and Agriculture, U.S. Department of Agriculture, Grant #3562104750. LSU supported this work by granting sabbatical leave to J.A.E. Much of this work was completed during a long-term visit to FMNH, which was supported by a Bass Senior Fellowship and the Barbara Brown Fund for Mammal Research. FMNH staff, including Larry Heaney, John Phelps, Adam Ferguson, Lauren Smith, and the late Bill Stanley were especially generous with their time. Also at FMNH, Lauren Nassef expertly prepared the specimen images in this manuscript. We thank the Collaborative Invertebrate Laboratories at the Field Museum, and P. Sierwald and R. Bieler for use of the imaging equipment (funded by NSF). We also thank Stephanie Ware for equipment training and support. At Museum Zoologicum Bogoriense, we received extensive support from Maharadatunkamsi, Nanang Supriatna, Endah Dwi Jayanti, and Apandi. Amy Adams at NMV and Spenser Babb-Biernacki and Ryan Eldridge at LSUMZ contributed to genetic data collection. Ben Evans gave essential advice and encouragement in the early stages of this project, well before we appreciated the depth of this rabbit hole. We thank Larry Heaney, Rob Voss, and an anonymous reviewer for their constructive reviews of an earlier version of this manuscript. 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