New remains of kollpaniine "condylarths" (Panameriungulata) from the early Palaeocene of Bolivia shed light on hypocone origins and molar proportions among ungulate-like placentals

2019 ● 41 ● 25 geodiversitas Geodiversitas est une revue en flux continu publiée par les Publications scientifiques du Muséum, Paris Geodiversitas is a fast track journal published by the Museum Science Press, Paris Les Publications scientifiques du Muséum publient aussi / The Museum Science Press also publish: Adansonia, Zoosystema, Anthropozoologica, European Journal of Taxonomy, Naturae, Cryptogamie sous-sections Algologie, Bryologie, Mycologie. Diffusion – Publications scientifiques Muséum national d’Histoire naturelle CP 41 – 57 rue Cuvier F-75231 Paris cedex 05 (France) Tél. : 33 (0)1 40 79 48 05 / Fax : 33 (0)1 40 79 38 40 [email protected] / http://sciencepress.mnhn.fr © Publications scientifiques du Muséum national d’Histoire naturelle, Paris, 2019 ISSN (imprimé / print) : 1280-9659/ ISSN (électronique / electronic) : 1638-9395 Directeur De la publication : Bruno David, Président du Muséum national d’Histoire naturelle réDacteur en chef / Editor-in-chiEf : Didier Merle assistants De réDaction / AssistAnt Editors : Emmanuel Côtez ([email protected]) Mise en page / PAgE lAyout : Emmanuel Côtez coMité scientifique / sciEntific boArd : Christine Argot (MNHN, Paris) Beatrix Azanza (Museo Nacional de Ciencias Naturales, Madrid) Raymond L. Bernor (Howard University, Washington DC) Alain Blieck (chercheur CNRS retraité, Haubourdin) Henning Blom (Uppsala University) Jean Broutin (UPMC, Paris) Gaël Clément (MNHN, Paris) Ted Daeschler (Academy of Natural Sciences, Philadelphie) Bruno David (MNHN, Paris) Gregory D. Edgecombe (The Natural History Museum, Londres) Ursula Göhlich (Natural History Museum Vienna) Jin Meng (American Museum of Natural History, New York) Brigitte Meyer-Berthaud (CIRAD, Montpellier) Zhu Min (Chinese Academy of Sciences, Pékin) Isabelle Rouget (UPMC, Paris) Sevket Sen (MNHN, Paris) Stanislav Štamberg (Museum of Eastern Bohemia, Hradec Králové) Paul Taylor (The Natural History Museum, Londres) couverture / covEr : Made from the figures of the article. Geodiversitas est indexé dans / Geodiversitas is indexed in: – Science Citation Index Expanded (SciSearch®) – ISI Alerting Services® – Current Contents® / Physical, Chemical, and Earth Sciences® – Scopus® Geodiversitas est distribué en version électronique par / Geodiversitas is distributed electronically by: – BioOne® (http://www.bioone.org) Les articles ainsi que les nouveautés nomenclaturales publiés dans Geodiversitas sont référencés par / Articles and nomenclatural novelties published in Geodiversitas are referenced by: – ZooBank® (http://zoobank.org) 841 GEODIVERSITAS • 2019 • 41 (25) © Publications scientifiques du Muséum national d’Histoire naturelle, Paris. www.geodiversitas.com Christian de MUIZON Guillaume BILLET Sandrine LADEVÈZE CR2P (CNRS, MNHN, Sorbonne Université), Département Origines et Évolution, Muséum national d’Histoire naturelle, case postale 38, 57 rue Cuvier, F-75231 Paris cedex 05 (France) Submitted on 26 February 2019 | accepted on 27 June 2019 | published on 19 December 2019 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia shed light on hypocone origins and molar proportions among ungulate-like placentals KEY WORDS Kollpaniinae, “condylarths”, early Palaeocene, Bolivia, hypocone, pseudohypocone, molars relative proportions. urn:lsid:zoobank.org:pub:4EF01B8A-BA1D-4F14-9432-CA8754D765D2 Muizon C. de, Billet G. & Ladevèze S. 2019. — New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia shed light on hypocone origins and molar proportions among ungulate-like placentals. Geodiversitas 41 (25): 841-874. https://doi.org/10.5252/geodiversitas2019v41a25. http://geodiversitas.com/41/25 ABSTRACT The description of new specimens of kollpaniines “condylarths” from Tiupampa (early Palaeocene of Bolivia) represents a significant addition to the knowledge of the earliest fauna of South American ungulates. Several partial mandibles and maxillae of Molinodus suarezi and Simoclaenus sylvaticus are described. The morphology of the lower premolars of Molinodus, being associated to lower molars, is established and a previous referral of an isolated p4 is rejected. A maxilla of Simoclaenus reveals the morphology of the so far unknown P1-4 of this taxon and allows a discussion on the development of the protocone in Palaeocene “condylarths”. The subvertical maxilla-premaxilla suture and the vertical implantation of the P1/p1 confirm the shortness of the snout of Simoclaenus, whereas the procumbency of the p1 of Molinodus indicates a longer rostrum. The upper molars of Molinodus confirm the presence of a tendency to duplication of the protocone, which is regarded as the incipient development of a pseudohypocone. The various patterns of formation of a hypocone (or pseudohypocone) are considered and, among other South American Native Ungulates, a protocone-derived pseudohypocone (i.e. Molinodus-like) is hypothesized in Lamegoia, Raulvaccia, and notoungulates, whereas a postcingulum-derived, hypocone is present in didolodontids and litopterns. The new specimens confirm the conspicuous small size of the M1/m1 of Molinodus and Simoclaenus as compared to the M2/m2. Consequently, we examined the relative proportions of molars in these taxa as compared to a variety of extant and extinct euungulates. Their proportions were plotted into the ‘developmental’ morphospace based on the predictive mathematical model of Kavanagh et al. (2007) (Inhibitory Cascade Model, or IC model), which might explain a large part of the mammalian diversity in molar proportions. Based on the upper molars, the Tiupampa kollpaniines were retrieved in a separate area of the predicted morphospace with other North American “condylarths” with large M2; this departure is also consistent with previous results concerning the lower molars (large m2). These peculiar molar proportions were found distinct from many other mammals, and might represent clade-specific differences: the large size of both the upper and lower second molars relative to other molars thus possibly representing a derived character state shared by some “condylarths” and kollpaniines. 842 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. MOT CLÉS Kollpaniinae, « condylarthres », Paléocène inférieur, Bolivie, protocone des prémolaires, hypocone, pseudohypocone, proportions relatives des molaires. RÉSUMÉ De nouveaux restes de « condylarthres » kollpaniinés (Panameriungulata) du Paléocène inférieur de Bolivie contribuent à l’interprétation des origines de l’hypocone et des proportions des molaires chez les placentaires à morphologie d’ongulés. La description de nouveaux spécimens de « condylarthres » kollpaniinés de Tiupampa (Paléocène inférieur de Bolivie) constitue un complément d’information significatif à la connaissance de la plus ancienne faune d’ongulés sud-américains. Plusieurs mandibules et maxillaires partiels de Molinodus suarezi et Simoclaenus sylvaticus sont décrits. La morphologie des prémolaires inférieures de Molinodus, étant associées à des molaires, est établie et l’attribution antérieure d’une p4 isolée à ce taxon est rejetée. Un maxillaire de Simoclaenus révèle la morphologie, inconnue auparavant, des P1-4 de ce taxon et permet une discussion sur le développement du protocone des prémolaires chez des « condylarthres » du Paléocène. La suture maxillaire-prémaxillaire, subverticale, et l’implantation verticale des P1/p1 confirme la faible longueur du museau de Simoclaenus, tandis que la p1 de Molinodus, légèrement proclive, indique un rostre plus long. Les molaires supérieures de Molinodus confirment la présence d’une tendance la duplication du protocone qui est considérée comme le développement initial d’un pseudohypocone. Les modalités de formation d’un hypocone (ou pseudohypocone) sont considérées et, parmi les autres ongulés natifs sud-américains, l’hypothèse de la formation d’un pseudohypocone, dérivé du protocone (de type Molinodus), est proposée chez Lamegoia, Raulvaccia et les notongulés, tandis qu’un vrai hypocone, dérivé du postcingulum, est présent chez les didolodontes et les litopternes. Les nouveaux spécimens confirment la petite taille des M1/m1 de Molinodus et Simoclaenus par rapport aux M2/m2. Les proportions relatives des molaires ont donc été examinées chez ces taxons et comparées à plusieurs euongulés actuels et fossiles. Leurs proportions ont été reportées sur un graphe dans l’espace morphologique de développement fondé sur le modèle mathématique prédictif de Kavanagh et al. (2007) (Inhibitory Cascade Model), qui pourrait expliquer une grande partie de la diversité des proportions des molaires de mammifères. Sur la base des molaires supérieures, les kollpa niinés de Tiupampa se situent dans une aire séparée de l’espace morphologique prédit, et ce, avec d’autres « condylarthres » nord-américains (possédant une grande M2). Cet écart est consistant avec les résultats antérieurs concernant les molaires inférieures (grandes m2). Ces proportions particulières sont différentes de celles de nombreux autres mammifères et pourrait représenter une spécificité de clade concernant les tailles relatives des molaires : la grande taille des deuxièmes molaires supérieures et inférieures pourrait donc constituer un caractère dérivé partagé par certains « condylarthres » et les kollpaniinés. INTRODUCTION The locality of Tiupampa (Cochabamba, Bolivia) has yielded the oldest mammalian assemblage of the Cenozoic of South America and is the type locality of the Tiupampan South America Land Mammal Age (SALMA), (Gelfo et al. 2009). The only possibly older Cenozoic mammal of South America is an isolated lower molar of polydolopimorphian (Cocatherium lefipanum) from the Lefipan Formation at the Grenier farm (Chubut, Argentina) and discovered in beds located about 5 m above the K-T boundary (Goin et al. 2006). A recent revision of Palaeogene SALMAs agreed with this view and considered a 64 Ma age for the Tiupampan (Woodburne et al. 2014a). The age of the Tiupampan has been reconsidered more recently and is regarded as closer to 65 Ma (early Danian), (Muizon et al. 2015, 2018). The Tiupampa mammals have been recovered from beds regarded as belonging to the chron 28r (Marshall et al. 1997; Gelfo et al. 2009), which, according to Wilson (2013, 2014) and Sprain et al. (2015), is bracketed between c. 65 Ma and 64.866 Ma. It is regarded as an equivalent of the earliest Torrejonian 1 of North America. The Tiupampa fauna includes only eutherians and metatherians, both of which are taxonomically abundant (12 metatherians and 11 eutherians). Some taxa are exceptionally well represented by partial to sub-complete skulls and skeletons. Among eutherians the pantodont Alcidedorbignya inopinata is the most abundant taxon and is known by three adult skulls, one of them being associated to an almost complete skeleton (Muizon et al. 2015). However, the most diverse eutherians at Tiupampa are the “condylarths”. “Condylarthra” is currently viewed as “an assortment of ungulategrade Palaeogene mammals” (Shelley et al. 2018: 2) and therefore probably polyphyletic (e.g., Halliday et al. 2017). The Tiupampa “condylarths” are represented by five genera and seven species, which are included in the same, so far endemic, sub-family of Mioclaenidae, the Kollpaniinae (Muizon & Cifelli 2000). The five genera of Kollpaniinae have a very similar morphological pattern and constitute a monophyletic taxon in most phylogenetic hypotheses (Muizon & Cifelli 2000; Gelfo 2007; Gelfo & Sigé 2011). Kollpaniinae have not been discovered in other localities of South America yet, but it is noteworthy that Tiupampan beds have not been identified elsewhere than in Tiupampa 843 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) either. The oldest Cenozoic mammalian fauna in South America after that of Tiupampa is that of Punta Peligro (Argentina), which has been regarded as late Palaeocene in age (Peligran = early Selandian, c. 61 Ma, Woodburne et al. 2014a). However, Woodburne et al. 2014b and Clyde et al. (2014) refer the Punta Peligro fauna to the late Danian with an age of c. 63.5 Ma. So far, no kollpaniine “condylarths” have been recovered at Punta Peligro. One single tooth outside Tiupampa has been referred to the Mioclaenidae and, as such, bears similarities with the Kollpaniinae. This specimen is the holotype of Pascualodus patagoniensis and is from the late Casamayoran (Barrancan = Bartonian) of Patagonia Argentina (c. 40 Ma) (Gelfo 2004). Therefore, in the present state of our knowledge, the Tiupampa “condylarth” fauna, taxonomically diverse at generic level (5 taxa) but very homogeneous at subfamilial level (Kollpaniinae), represents the oldest known evidence of the ungulate-like placentals radiation in South America. Kollpaniines, which are potentially related to litopterns (Muizon & Cifelli 2000), may in fact document one of the first steps of the diversification of South American Native Ungulates (SANUs) on this continent. Recent proteomic and mitogenomic data showed that litopterns and notoungulates are closely related to the Perissodactyla (Welker et al. 2015; Buckley 2015; Westbury et al. 2017), an order of mammals still represented today and probably originating from northern continents (Cooper et al. 2014; Rose et al. 2014; Bai et al. 2018). According to these hypotheses, the Notoungulata and Litopterna would thus also belong to the Euungulata together with the Perissodactyla and Artiodactyla (Asher & Helgen 2010). The divergence between Litopterna and Perissodactyla was estimated close to 66 Ma (Westbury et al. 2017), which confers considerable importance to the fossil kollpaniines from Tiupampa (estimated c. 65 Ma) to further disentangle the phylogenetic and spatiotemporal aspects of this divergence. However, the fossil remains of Tiupampa kollpaniines, although relatively abundant, are not as well preserved as those of Alcidedorbignya since they are only represented by isolated jaws and some postcranial elements, which are most of the time, not associated. Therefore, the fossil record of the Kollpaniinae is relatively incomplete and any new specimen is susceptible to improve substantially the knowledge of this group. Since the description of the Tiupampa kollpaniine fauna (Muizon & Cifelli 2000), several field expeditions have been undertaken at Tiupampa, which have unearthed some interesting new kollpaniine specimens. Here, we describe these new specimens with an aim at providing critical anatomical information on this early diversification and on potential phylogenetic relationships to other “condylarths” and to SANUs. The description of these remains also involves considerations on the hypocone formation within these groups and a comparison of the peculiar molar proportions found in kollpanines with other “condylarths” and ungulate or ungulate-like mammals within the frame of recently developed evo-devo models on this aspect (Kavanagh et al. 2007; Polly 2007). MATERIAL AND METHODS In this paper, we intend to describe the most relevant new specimens of kollpaniines collected at Tiupampa, which are referred to five species belonging to four genera, Molinodus suarezi, Simoclaenus sylvaticus, Tiuclaenus minutus, Tiuclaenus robustus, and Pucanodus gagnieri. No new specimens of Andinodus boliviensis have been recovered, and, so far, the only known specimens of this taxa are the two lower jaw fragments described by Muizon & Cifelli (2000). The most abundant kollpaniine taxon at Tiupampa is Molinodus suarezi. Three partial mandibles respectively with p3-m3 (MHNC 13867), m2-3, (MHNC 13871) and c-p1 (MHNC 13883), and one left partial maxilla with M1-3 (MHNC 13870) substantially increment the knowledge of the dental anatomy of this taxon. Simoclaenus sylvaticus is a relatively rare taxon at Tiupampa and was up to now only known from two specimens, the holotype, a partial mandible with p4-m3, and a partial maxilla with M1-3. The new specimens of S. sylvaticus are a partial maxilla with the root of the canine and P1-4 (MHNC 13868), a partial maxilla with M1-2 (MHNC 13876), and a partial mandible with roots of p2-3 and p4-m1 (MHNC 13872). A partial maxilla with M1-3 (MHNC 13879), is referred to Tiuclaenus minutus and a partial mandible with m2-3 (MHNC 13875) is referred to T. robustus. A partial mandible with almost unworn m2-3 (MHNC 13869) is referred to Pucanodus gagnieri. The other specimens are either poorly preserved or not informative as compared to the specimens already described in Muizon & Cifelli (2000). In the Systematic Palaeontology section below, concerning the data on the locality we refer to Muizon & Cifelli (2000). For the section “Horizon and Age” we refer to Muizon et al. (2015, 2018 ). When necessary the diagnoses provided by Muizon & Cifelli (2000) is emended. The terminology used here for molar morphology follows Muizon & Cifelli (2000: fig. 1). The measurements of upper molar areas were taken on photographs of occlusal surfaces in kollpaniins, many euungulates (e.g., artiodactyls, perissodactyls, notoungulates, litopterns) and ungulate-like mammals (e.g., “condylarths”), and also on several “cimolestans” used as potential outgroups. The same was also undertaken for lower molars in kollpaniins. Photographs were taken with the occlusal surface and the lens of the camera oriented parallel to each other with a scale placed parallel to, and at the same height as the occlusal plane. Molar outlines were drawn and areas were calculated with the software ImageJ (Rasband 1997-2018) at the level of the collar for brachydont species and at the occlusal surface for hypsodont species. Only hypsodont species with unvarying (or weakly varying) molar dimensions along their crown height were included. No hypselodont species (ever-growing teeth) were included. We plotted the relative molar proportions of each taxon in a morphospace described 844 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. by the ratios of molar areas of M2/M1 and M3/M1, as in previous studies interested on molar proportions (e.g., Kavanagh et al. 2007; Polly 2007; Wilson et al. 2012; Halliday & Goswami 2013; Carter & Worthington 2016) (note that these studies were interested on lower molars, while this part of our study is mainly focused on upper ones; see below). This corresponds to the ‘developmental’ morphospace as introduced by Polly (2007) and based on the predictive mathematical model of Kavanagh et al. (2007) (Inhibitory Cascade Model or IC model), which initially aimed at predicting the diversity in lower molar proportions among murine rodents. Polly demonstrated that Kavanagh et al.’s model was also powerful for a wider array of mammals (see also Wilson et al. 2012; Halliday & Goswami 2013; Carter & Worthington 2016). InstItutIonal abbrevIatIons AMNH American Museum of Natural History, New York, United States; DGM Divisão de Geología e Mineralogía do Departamento Nacional da Produção Mineral , Rio de Janeiro, Brazil; GI-PST Institute of Geology, Section of Palaeontology and stratigraphy, Mongolian academy of Sciences, Ulaan Baatar, Mongolia; IITR/SB/VLR Vertebrate Palaeontology Laboratory, Department of Earth Sciences, Indian Institute of Technology, Roorkee, India; HGSP Howard University/Geological Survey of Pakistan, Islamabad, Pakistan; MACN Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina; MCZ-VP Harvard University, Museum of Comparative Zoology, vertebrate paleontology, Cambridge, Massachusetts, United States; MNRJ Museu Nacional e Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; MHNC Museo de Historia Natural “Alcide d’Orbigny”, Cochabamba, Bolivia; MHNM Natural History Museum of Marrakech, Morocco; MLP Museo de La Plata, La Plata, Argentina; MNHN.F Muséum national d’Histoire naturelle, Palaeonto logical collection, Paris, France; NMMNH New Mexico Museum of Natural History and Science, Albuquerque, NM, United States; PSS-MAE Paleontological and stratigraphy Section (Geological Institute), Mongolian Academy of Sciences, Ulaan Baatar, Mongolia; RR Rangarao-Obergfell Trust for Geosciences, Dehra Dun, India; UALVP University of Alberta, Department of Biological Sciences, Laboratory for Vertebrate Paleontology, Edmonton, Canada; UCMP Museum of Paleontology, University of California, Berkeley, United States; UM University of Michigan Museum of Paleontology, Ann Arbor, Michigan, United States; USNM United States National Museum, Smithsonian Institution, Washington, DC, United States; YPFB Yacimientos Petrolíferos Fiscales de Bolivia; YPM-PU Princeton University collection housed in the Yale Peabody Museum, Yale University, New Haven, Connecticut, United States; Z. Pal Paleontological Institute of the Polish Academy of Sciences, Warsaw, Poland. SYSTEMATIC PALEONTOLOGY Order PANAMERIUNGULATA Muizon & Cifelli, 2000 Family MIoclaenIdae Osborn & Earle, 1895 Subfamily KollpanIInae Marshall, Case & Woodburne, 1990 Molinodus suarezi Muizon & Marshall, 1987 eMended dIagnosIs. — Size similar to that of Promioclaenus; dental formula I?/3, C?/1, P?/4, M3/3; P3 triangular, with a strong parastyle anterior to paracone; preand postparacristae well-developed; protocone is a well-developed cusp and distincly individualized from the paracone but slender with slight preand postcingula; P4 more massive, shorter, and wider than P3, with small conules; protocone only slightly larger than on P3 but more massive; wellmarked preand postcingula, and strong labial cingulum; M1 triangular and almost symmetrical in relation to its transverse axis; protocone transversely compressed with an oval-shaped apical wear facet; metacone only slightly lingual to the paracone; welldeveloped cingula (pre-, postand labial); styles slightly to not projected labially; no hypocone; M2 subquadrangular and strongly asymmetrical, with oblique labial edge; well-developed preand postcingula, not reaching the paraand metastyles (but close to them); labial cingulum very strong; protocone large, bulbous, and mesiodistally elongated with incipient duplication; conules large; well-developed paraand metacingula reaching paraand metastyles; paracone higher and more voluminous than metacone; metacone much more lingual than paracone; centrocrista straight; paraand metastyles almost aligned with paraand metacones but parastyle still slightly shifted labially; no well-individualized hypocone; M3 much wider than long; strongly bent posteriorly; labial edge strongly oblique; little reduced (i.e. only slightly shorter than M2); metacone and metaconule reduced; i1 and i2 distinctly larger than i3; i2 staggered; lower canine short and robust; p1 single-cusped, single-rooted, and procumbent; p2 triangular in lateral view; transversely flattened; small posterior cusp; p4, much larger; variable in shape from triangular to quadrate, with a large metaconid appressed against protoconid; anterior crest of protoconid possessing a tiny paraconid; large talonid cusp; lower molars with bulbous cusps; trigonid and talonid basin reduced; strong preand small postcingulids (on m1 and m3 only); paraconid clearly smaller than and appressed against metaconid; paracristid transverse and arched distally; metaconid distolingual to and slightly smaller than protoconid; cristid obliqua variable in size and reaching labial edge of metaconid; talonid basin small and open lingually (more an oblique groove than a basin); hypoconid large, inflated, circular, and only slightly smaller than protoconid; entoconid and hypoconulid almost completely fused forming a distolingual oblique crest; talonid of m3 larger than on m1-2 with hypoconulid as large as hypoconid. On the dentary presence of a well-developed coronoid crest separated from the labial edge of m3 by a coronoid fossa. Among Tiupampa “condylarths”, Molinodus more resembles Simoclaenus than the other taxa. However, Molinodus differs from Simoclaenus in its smaller size, its cheek teeth more elongated mesiodistally, its upper molar less transverse, its M2 more asymmetrical with an mesiolabially projected parastyle, its procumbent p1, and its longer rostrum. Molinodus differs from Promioclaenus in its molars, which are more bulbous with apices of the cusps more approximated, in the longer trigonid of the lower molars with a paraconid less appressed against the metaconid, in the presence of a generally distinct labial cingulum, in the non-reduced m3, in the more transverse and less bulbous upper molars, in the thinner postcingulum, in the strong asymmetry of the M2 with an mesiolabially projecting parastyle, and in the unreduced M3. 845 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) HypodIgM. — As in Muizon & Cifelli (2000) with the additional following specimens: MHNC 13883, a partial left mandible with alveoli of incisors, canine, p1, roots of p2, alveoli of p3 and alveolus of anterior root of p4; MHNC 13867, a partial left mandible with p3-m3; MHNC 13870, a partial left maxilla with M1-M3, with M1 and M2 missing the labial edges of paraand metacones. descrIptIon An anterior fragment of left mandible of Molinodus suarezi (Fig. 1) bears the labial edge of the alveoli of the three incisors, the canine, the p1, the roots of p2, the alveoli of p3, and the anterior alveolus of p4 (MHNC 13883). On the medial aspect of the dentary a large symphyseal surface for the intermandibular suture is present. This surface is in one plane with sharp edges, but it is rough and bears numerous ridges and grooves probably interlocking with the symmetrical surface on the other mandible. The two symphyseal surfaces were therefore tightly attached one to the other, but the symphysis was clearly unfused on this specimen. Although ligamentous, it is likely that the symphysis was quite rigid and allowed little intermandibular movements. Because the roots of p3 extends as far as the ventral region of the dentary leaving no space of a potential unerupted tooth germ, we regard that the definitive p3 was erupted. Because the preserved teeth (c and i1) are absolutely unworn, this specimen is interpreted as belonging to a young adult. It is, therefore, not impossible that ontogenetically older individuals may have had a fused symphysis. On the labial side of the dentary a large anterior mental foramen is present ventral to the embrasure between p1 and p2. Although the incisors are missing, the anteriormost region of the dentary is preserved with the labial edge of the incisors alveoli. The dentary is broken vertically in this region and the lingual portion of the alveoli is missing; therefore, a vertical section of the incisors alveoli can be observed. Based on the size of the roots, i1 was apparently the largest of the three incisors or was, at best, similar in size to i2. The i3 is clearly the smallest of the three incisors. Interestingly, the alveolus of i2 presents a distinct lingual shift of its root. As a consequence, the vertical section the alveolus is clearly triangular whereas alveolus of i3 alveolus of i2 alveolus of i1 canine alveolus of i1 alveolus of i2 p1 mandibular symphysis canine alveoli of p3 anterior alveolus of p4 mental foramen incisors alveolar border roots of p2 alveoli of p3 anterior alveolus of p4 p1 canine alveolus of i3 A B CDE posterior cuspule posterior cuspule roots pf p2 fig. 1. — Molinodus suarezi: anterior portion of a right mandible (MHNC 13883) bearing the alveoli of I1-3, the canine, the p1, the roots of p2, partial alveoli of p3 and the lateral wall of the anterior alveolus of p4 in: A, labial view; B, lingual view; C, anterodorsal view; D, dorsal view; E, medial view of the lateral wall of the incisors showing the V-shaped morphology of the alveolus of i2, which indicates that the tooth was staggered. Scale bar A-D: 5 mm; E, 3 mm. 846 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. A B C fig. 2. — Partial left mandible of Molinodus suarezi (MHNC 13867) bearing p3-m3: A, stereophotographs of the occlusal view; B, lingual view; C, labial view. Scale bar: 5 mm. 847 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) that of the other alveoli are cylindrical with parallel edges (Fig. 1B, E). This condition of the i2 of Molinodus, is identical to the staggered second incisor, (the i3 according to Hershkovitz 1982, 1995), of many metatherians (e.g., stagodontids, pucadelphyids, sparassodonts, didelphids, microbiotheres, peramelids, thylacinids, dasyurids). The triangular section of the alveolus of the staggered incisor is clearly observed on the figure 5 of Hershkovitz (1982). It is not the first time that a staggered second incisor is described in a eutherian since Hershkovitz (1982: 197) mentions this condition in several extant Carnivora. Among the Tiupampa eutherians, it is absent in Alcidedorbignya inopinata (Muizon et al. 2015), and there is no indication that it was present in Tiuclaenus minutus and Pucanodus gagneri, the only other Tiupampa eutherians that preserve the anterior portion of the dentary. It may be the first time that this trait is observed in a fossil eutherian, but this is probably due to the fact that the anterior portion of the dentary is rarely preserved in fossil mammals. In dorsal view, the three lower incisors are set in a slightly oblique row, relative to the symphyseal plane (Fig. 1C). In other words, i1 is anteromedial to i2, and i3 is posterolateral to i2. The lower incisor tooth row was, therefore, more or less parabolic or V-shaped. The last incisor, i3, was closely appressed against the mesial edge of the canine as indicated by the position of the i3 alveolus. The canine is a moderately developed tooth but it is robust. The height of the crown (4.60 mm) is approximately twice its mesio-distal length (2.44 mm) at base. The canine is transversely compressed, being distinctly narrower (1.75 mm) at its base than long (2.44 mm). The posterior curvature of the canine is weak and its posterior edge is only very slightly concave. Its mesial edge is distinctly convex. On the mesiolingual edge of the tooth a blunt ridge extends mesioventrally on the dorsal half of the crown and distoventrally on the ventral half (Fig. 1B). In dorsal view, the labial side of the canine is strongly convex, whereas it is almost flat to slightly concave on its lingual side. In labial view the main axis of the crown is moderately oblique in relation to the alveolar plane, with which it forms an angle of approximately 110°. table 1 . — Comparative measurements (in mm) of the lower molar in Molinodus suarezi. Abbreviations: L, length; W, width of trigonid. m1 L m1 W m2 L m2 W m3 L m3 W YPFB Pal 6112 3.15 2.34 3.69 2.82 3.98 2.43 YPFB Pal 6113 3.47 2.89 3.78 3.30 4.30 – MHNC 8269 3.13 2.30 3.60 2.74 4.72 2.80 MHNC 13867 3.29 2.20 3.83 2.71 4.71 2.71 coronoid crest coronoid crest coronoid crest coronoid fossa coronoid fossa coronoid fossa ABC fig. 3. — Molinodus suarezi: A, dorsal view of MHNC 13867; B, dorsal view of a partial left mandible bearing m2-3 (MHNC 13871) showing the robust extension of the coronoid crest on the lateral side of the dentary and the deep fossa, which separates the crest from the talonid of m3; C, the same in labial view. Scale bar: 5 mm. 854 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. mm) is only slightly smaller than the lower premolar row of the holotype of S. sylvaticus (11.97 mm), on which the alveoli of p1-3 and the p4 are preserved. Therefore, the mesiodistal length of the upper premolar row of the new specimen (MHNC 13868) correctly matches the length of the lower premolars row of the holotype (MHNC 8348). P1 is peg-like, single-rooted, and compressed transversely. It is implanted vertically in the maxilla as is observed on the alveolus of the p1 of the holotype (MHNC 8348). This condition suggests a relative shortness of the rostrum and is congruent with the anteroposterior compression of the lower cheek teeth observed on the mandible. It is noteworthy that the p1 of Molinodus described above (MHNC 13883) differs from the condition observed in Simoclaenus in being slightly procumbent, thus suggesting a more elongated rostrum. As preserved, the P1 of Simoclaenus on MHNC 13868 is longer than high and no significant wear facet can be observed at the apex of its crown. In lateral view the tooth is roughly symmetrical anteroposteriorly. A small diastema separates P1 from the canine anteriorly and from P2 posteriorly. P2 is triangular in occlusal view and bears three roots. It is longer than wide. It presents a conspicuous inflation on its distolingual edge, which can be regarded as an incipiently developed protocone (protoconal bulge). The paracone forms most of the tooth and is as high as long. Its mesial edge is wide and blunt whereas its distal edge is thin and forms a sharp crest. The tooth bears no cingulum but a small cusp at the distolabial edge of the paracone could be regarded as a metastyle. This style contacts the anterior edge of P3 and no diastema separates the two teeth. P3 is slightly wider than long, triangular in occlusal view, and bears three roots. The mesial and distal edges are markedly concave, a condition which individualizes a well-developed protocone lingually. This cusp is approximately two thirds the height of the paracone. It is as long as wide. It has a very convex lingual edge and a flat labial aspect. These two edges of the tooth are separated by sharp preand postprotocristae, which join the base of the crown at the level of the greatest concavity of the mesial and distal edges of the tooth. Labially the paracone is approximately twice as long as wide. Its mesial edge bears a smooth crest and its distal crest is slightly obliterated by an elongated wear facet, which extends from the apex of the tooth to the posterior base of the paracone. At the mesial angle of the paracone is a marked parastyle. From this cusp, a conspicuous cingulum extends on labial edge of the paracone. At the distal end of the cingulum is a small metastyle. P4 has a pattern similar to that of P3 but it is mesiodistally shorter and transversely wider. Its mesial and distal edges are slightly concave but to a much lesser extent than the condition observed on P3. The paracone is smaller (in height and volume) and the protocone is more voluminous than on the preceding tooth. The preand postprotocristae are more developed than on P3 and extend on the anterior and posterior edges of the paracone. The postprotocrista even joins the distolabial angle of the tooth and contacts the postparacrista. The latter bears a narrow wear facet on its mesial two thirds only. The distal end of the postparacrista bears, on its lingual aspect, a hint of inflation, which can be interpreted as an incipient metacone. A tiny inflation on the postprotocrista may also be regarded as an incipient metaconule. On the distal edge of the protocone, is a distinct postcingulum. On its mesial edge the precingulum is weakly developed. On the mesiolabial angle of the tooth the parastyle is more developed than on P3. From this style, a well-developed labial cingulum extends distally until the metastylar angle of P4. fig. 9. — Simoclaenus sylvaticus: partial right maxilla with M1-2 (MHNC 13876), stereophotograph of occlusal view. Scale bar: 5 mm. 855 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) Little is preserved of the palatal process of the maxilla, but the lateral wall of the rostrum from the anterior edge of the canine to the anterior root of the zygomatic arch is relatively complete and all its edges likely correspond to sutures with adjacent bones except for a small U-shaped-break in the posterodorsal angle (Fig. 8C). The anterodorsal edge of the specimen probably corresponds to the nasal-maxilla suture. Approximately above the P1-P2 embrasure, the edge of the maxilla distinctly protrudes medially. Anterior to this indentation, the suture is apparently anteroposteriorly oriented or slightly oriented anterolaterally. Posterior to it, the suture diverges posterolaterally, thus indicating a widening of the nasals posteriorly, as generally observed in early diverging metatherians and eutherians (e.g., deltatheroidans, pucadelphydans, Zalambdalestes, Kulbeckia, Alcidedorbignya). On the posterior limit of the maxilla, as preserved, is a deep groove probably for the articulation of the anterior process of the jugal. This groove (maxillajugal suture) approximately corresponds to the level of the anterior edge of the orbit and the posterior limit of the rostrum, which corresponds to the posterior edge of P4. On the posterodorsal angle of the specimen, in lateral view, is a distinct small notch (dorsal to the breakage notch mentioned above), which was receiving the anterolateral angle of the frontal. If this interpretation is correct, the nasal and lacrimal of Simoclaenus were distinctly separated, which likely represents a crown Placentalia condition (frontal-maxilla suture present) (Muizon et al. 2015). The posterior edge of the maxilla, between this notch and the dorsal end of the jugal groove, likely corresponds to the lacrimal-maxilla suture. Anteriorly, several grooves mark the edge of the maxilla immediately anterior to the canine, which we interpret as the premaxilla-maxilla suture. This suture is almost straight, slightly concave anteriorly, and sub-vertical, forming an angle of approximately 95° with the alveolar plane (Fig. 8C). The lateral aspect of the maxilla is markedly elevated and erected, to a greater extent than the condition observed in the pantodont Alcidedorbignya inopinata from the same locality (Muizon et al. 2015). This condition apparently resembles that of Baioconodon nordicum (YPM-PU 14234) from the earliest Palaeocene (Puercan) of Mantua lentil of Wyoming. The anterior opening of the infraorbital canal is 2.08 mm high and located above the mesiolabial root of P3. In this respect Simoclaenus differs from the condition in Maiorana and Baioconodon, in which the infraorbital foramen is located more posteriorly, above the mesiolabial root of P4. A condition similar to that of Maiorana and Baioconodon is observed in Didolodus multicuspis (MACN 10690), in which the infraorbital foramen is located above the distal edge of P3 and most of the P4 (Gelfo, personal communication). Anterior to this foramen is a tiny opening located above the anterior root of P2, and which probably represents a nutrient foramen. In its anterior region, the maxilla is not inflated laterally by the canine as is observed in Alcidedorbignya, due to the fact that the canine was compressed transversely. This condition particularly resembles the “condylarths” of Mantua lentil of Wyoming, Baioconodon and Maiorana. The third specimen referred to Simoclaenus sylvaticus is a partial maxilla with M1-2 (MHNC 13876), (Fig. 9). The M2 perfectly matches the size and morphology of that of MHNC 8348 described by Muizon & Cifelli (2000). The small differences between the two teeth are the presence, in MHNC 13876, of a slightly larger parastyle, a cuspule on the preparaconular crista located between the paraconule and the parastyle and a slight inflation of the lingual end of the precingulum (cuspule?). The M2 of MHNC 13876 has the characteristic asymmetrical morphology observed in Molinodus and Simoclaenus, in which the paracone is distinctly more labial than the metacone (Muizon & Cifelli 2000: fig. 2A-C, fig. 14C). This condition is not observed on the M1 of Molinodus, the paracone of which is not shifted labially. The most interesting characteristic of this specimen is in the relative wear stage of the M2 and M1. The M2 has a wear stage approximately similar to that of the M2 of MHNC 8348. In contrast the M1 is totally excavated in its lingual two thirds: the protocone, the protocristae and the conules, the pre-and postcingula, and the trigon basin have disappeared; the only preserved elements of the tooth are the paraand metacones, the styles and the labial cingulum. This wear stage is clearly more advanced than that observed on the M1 of MHNC 8348, in which the protocone and conules are coalescent but still identifiable, the protocristae and the pre-and postcingula are distinctly observable. This stage of wear of M2-1 of MHNC 8348 is comparable to that observed on the maxilla of Molinodus suarezi (MHNC 1247) described by Muizon & Cifelli (2000). In fact, the extensive wear of the M1 of MHNC 13876 is comparable to the condition that could be observed on a DP4, an interpretation impossible given the fact that the posterior tooth is undoubtedly an M2, which presents the characteristic asymmetrical morphology of that tooth (Muizon & Cifelli 2000). Furthermore, the roots of the M1 are long and the lingual root perforates the floor of the orbit, which suggests that it is not a deciduous molar. In ventral view, laterally to M2, the maxillar process of the zygoma and the anterior border of the orbitotemporal fossa are preserved. The latter is at the level of the apex of the metacone of M2, while it is at the level of the paracone of M3 on the maxilla (MHNC 8348) referred to Simoclaenus by Muizon & Cifelli (2000). In Molinodus the anterior edge of the orbitotemporal fossa is at the level of the paracone of M3 and in Baioconodon (YPM-PU 14234) and Maiorana (YPM-PU 16667 and 14171) it is at the level of the metacone of M3. However, this condition is likely to be individually variable since in Alcidedorbignya inopinata out of 13 specimens, in which it can be observed, three of them (see Muizon et al. 2015: fig. 10B) have an anterior edge of the orbitotemporal fossa at the level of the metacone of M2, as observed in the Simoclaenus specimen described here. In the other ten specimens, the anterior edge of the fossa is at the level of the paracone of M3. In the Alcidedorbignya 856 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. sample the anterior position of M2 is observed in young adults and may be related to the ontogenetic increase of the length of the rostrum. Tiuclaenus minutus Muizon & Marshall, 1987 dIagnosIs. — See Muizon & Cifelli (2000). descrIptIon A maxilla with M1-3 (MHNC 13879) is referred to Tiuclaenus minutus. It bears three almost unworn molars, and has been referred to this species essentially on the basis of its size (Fig. 10A). Tiuclaenus minutus is the smallest “condylarth” species of the Tiupampa fauna and the molars of the new specimen are even slightly smaller than those of MHNC 1240 described by Muizon & Cifelli (2000: fig. 7C). For example, the length of the molar row is 5.86 mm in MHNC 13879, while it is 6.74 mm on MHNC 1240, but such a size dif - ference is likely related to individual variation. The size and proportions of the upper molar of this specimen depart from the other species of Tiuclaenus and from Pucanodus, which are distinctly larger (see Muizon & Cifelli 2000: tables 7-9). However, some slight morphological differences exist between the specimens referred to T. minutus, which differ in the larger size of the paraand metastyles, the para-and metacones more approximated, the more pronounced ectoflexus and labial cingulum. Nevertheless, in spite of these morphological differences we tentatively refer MHNC 13879 to T. minutus, considering that they could regarded as related to individual variation, an interpretation that could be revised when a larger sample of that species will be available. Tiuclaenus robustus Muizon & Cifelli, 2000 dIagnosIs. — See Muizon & Cifelli (2000). descrIptIon A right mandible fragment bearing m2-3 (MHNC 13875) has been referred to Tiuclaenus robustus (Fig. 10B, C) essentially because, although structurally similar to the other species of Tiuclaenus (T. minutus and T. cotasi), it differs from them in its size, distinctly larger, and in its greater massiveness. Furthermore, as is observed on the holotype (a mandible fragment with m2-m3, MHNC 1233), m3 of MHNC 13875 is proportionally shorter than in T. minutus and T. cotasi being barely longer than m2. An interesting feature of this specimen is the morphology of the roots of m2 and m3, which are long extending ventrally on more than 2.5 the height of the crown (Fig. 10C). Furthermore, the apices of the roots are markedly splayed with their posterior edges extending posteriorly, providing the extremity of the root a characteristic hammer-shape. Although the ventral edge of the dentary is partly broken, this morphology gives the impression that the root had to develop posteriorly because it was abutting the ventral edge of the mandibular canal. Pucanodus gagnieri Muizon & Marshall, 1991 dIagnosIs. — See Muizon & Cifelli (2000). descrIptIon A mandible fragment bearing m2-3 (MHNC 13869) has been referred to Pucanodus gagnieri (Fig. 11) because it presents the mesiodistal compression of the molars especially m3, which is characteristic of that species (Muizon & Marshall 1991). The specimen is approximately of the size of a small Tiuclaenus. The teeth are almost unworn and better illustrate this taxon than the holotype (a mandible with p3-m3), the teeth of which, are notably worn. The massive proportions of the teeth (large width relative to length) and particularly the shortness of the talonid of m3 are conspicuous on this specimen. As in all kollpaniines and North American mioclaenines, the entoconid and hypoconulid are connate (almost confluent) and the talonid basin is an obliquely oriented groove open anterolingually. Measurements are provided on Table 5. DISCUSSION dental locI and specIMen dIstrIbutIon The description of several new specimens of “condylarths” from the early Palaeocene of Tiupampa (Bolivia), although it does not increment the taxonomic list of the fauna, significantly improves the knowledge of the dental anatomy of the kollpaniine mioclaenids (Table 6). These new data essentially concern the upper and/or lower premolars, the morphology of the protocone, the size difference between M1/m1 and M2/m2, and the morphology of the lateral process of the maxilla of Simoclaenus. Among others, the new specimens of Simoclaenus sylvaticus described here confirm the shortness of the rostrum of this taxon on the basis of the vertical implantation of P1/p1, the mesiodistal shortness of p4, and the supposedly subvertical premaxilla-maxilla suture on the anterior region of the rostrum. In this respect, S. sylvaticus differs from Molinodus suarezi, in which p1 is procumbent, and p4 is not compressed mesiodistally, being much longer than wide. The total number of “condylarths” specimens with addition of the new specimens recovered since the review of Muizon & Cifelli (2000) reaches 89 specimens, which represents a significant source of data given the age of the Tiupampa fauna (early Danian). The abundance and jaw distribution of the specimens according to taxa is presented in Table 7. preMolars The mandible MHNC 13867 which bears p3-m3 provides an indication that the p4 referred to Molinodus by Muizon & Cifelli (2000: fig. 3 M, N) may not belong to this species. The newly described p4 of Molinodus (Fig. 2) is not anteroposteriorly compressed with a metaconid lingual to the protoconid, but is more slender, longer and narrower, and has a metaconid distolingual to the protoconid. 857 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) A BC fig. 10. — A, Tiuclaenus minutus: partial right maxilla of with M1-3 (MHNC 13879), stereophotograph of occlusal view; B, Tiuclaenus robustus: partial right mandible with m2-3 (MHNC 13875), stereophotograph of occlusal view; C, the same in labial view. Scale bar: 5 mm. 858 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. Furthermore, a maxilla with a complete series of upper premolars is referred to Simoclaenus sylvaticus (Fig. 8). The upper premolars of S. sylvaticus present a well-developed protocone on P3-4 (protocone of P3 is almost as developed as that of P4) and an incipiently developed protocone on P2 (just an inflation of the posterolingual angle of the tooth, a protoconal bulge, not individualized as a distinct cusp as on the posterior premolars). Although the P1 and P2 of Molinodus suarezi are unknown, the P3 of this taxon exhibits a large protocone as in S. sylvaticus. It is likely that the P1 and P2 of M. suarezi were similar to those of S. sylvaticus. Based on the condition observed on the middle-late Jurassic eutherian Juramaia sinensis (Luo et al. 2011), on the oetlestids Prokennalestes trofimovi and P. minor (Kielan-Jaworowska & Dashzeveg 1989), on the zhelestids Parazhelestes robustus and Aspanlestes aptap (Nessov et al. 1998; Archibald & Averianov 2005) and on the cimolestid Puercolestes simpsoni (Williamson et al. 2011), the plesiomorphic condition in eutherians would be a poorly-developed protocone on P3 or penultimate upper premolar (either a simple bulge or a very small cusp on the distolingual edge of P3) and a well-developed protocone (almost as large as the paracone) on P4. Therefore, Molinodus and Simoclaenus are clearly derived in this respect. They are more derived than the North American mioclaenid, Promioclaenus acolytus (e.g., USNM 9575, AMNH 32728) as well as the earliest Palaeocene (Mantuan) Baioconodon nordicum (YPM-PU 14234), in which the protocone is well-developed on P4, incipient on P3 and absent on P2 (CM personal observations). However, the condition of the P3 protocone may represent a labile and homoplastic feature since a wellindividualized protocone is present in some (but not all) specimens of Oxyprimus galadrielae (PU 21015) and in Maiorana noctiluca (PU 16667) from the basal Puercan of Mantua hills (Wyoming) as well as in Promioclaenus lemuroides (AMNH 4025). Furthermore, it is noteworthy that a well-developed protocone on P3 is also present in Zalambdalestes, Asioryctes and Kennalestes from the late Cretaceous of Mongolia (KielanJaworowska 1981; Wible et al. 2004). Among the other Tiupampa kollpaniines the upper premolars are known in Tiuclaenus cotasi, T. robustus, and PucanoAB fig. 11. — Pucanodus gagnieri: partial right mandible with m2-3 (MHNC 13869): A, stereophotograph of occlusal view; B, the same in labial view. Scale bar: 5 mm. 859 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) dus gagnieri (Muizon & Cifelli 2000: fig. 8A, 10G, 11B). The condition in these taxa differs from that of Molinodus and Simoclaenus since the protocone of P3 is significantly smaller than that of P4 and P2 in T. cotasi (P2 is unknown in T. robustus and P. gagnieri) has no protoconal bulge. Therefore, according to the plesiomorphic condition of zhelestids and cimolestids, Tiuclaenus and Pucanodus exhibit a less derived condition than Molinodus and Simoclaenus. Among other South American “condylarths” (e.g., Didolodontidae) a well-developed protocone is present on the P3-4 of the Casamayoran highly derived species Didolodus multicuspis (MACN 10690), but it is poorly developed on the P3 of the Itaboraian taxon Ricardocifellia protocenica (Paula Couto 1952a: pl. 32, fig. 1). Furthermore, in early litopterns from Itaboraí (i.e. Protolipternidae), the protocone of P3 is distinctly smaller than on P4 in Protolipterna ellipsodontoides (MCT-1495M) and possibly in Miguelsoria parayirunhor. In the latter, P3-4 are unknown but the specimen MNRJ 4094V, a maxilla with the three molars and a P2 with a protoconal bulge, presents the alveoli of P3-4, which are distinctly three-rooted, with the lingual root (receiving the protocone) of P3 conspicuously smaller than that of P4. This condition strongly suggests a P3 with a distinctly smaller protocone than on P4. The P3 lacks a well-developed protocone in Asmithwoodwardia scotti (Paula Couto 1952a: pl. 33 fig. 3). However, comparison is made difficult because a complete set of upper premolars is unknown in many early didolodontids (including the Peligran taxa Escribania and Raulvaccia). Pending more data are known on those taxa, the condition of Simoclaenus and Molinodus is regarded as probably more derived than that of most North and South American Palaeocene “condylarths”, since they exhibit a greater specialization in the process of development table 5. — Measurements of the kollpaniine specimens described in text (in mm). Taxon and Tooth Body part No. spec. Length Width Trig width Tal width Others Molinodus suarezi c MHNC 13883 2.44 1.75 – – – p1 MHNC 13883 1.56 1.23 – – – roots p2 MHNC 13883 2.59 – – – – p3 MHNC 13867 3.18 1.94 – – – p4 MHNC 13867 3.23 2.03 – – – m1 MHNC 13867 3.29 – 2.20 1.99 – m2 MHNC 13867 3.83 – 2.71 2.60 – m3 MHNC 13867 4.71 – 2.71 2.39 – Height of dentary below m2 dentary MHNC 13867 – – – – 7.13 Simocalenus sylvaticus roots p2 MHNC 13872 2.42 – – – – roots p3 MHNC 13872 2.77 – – – – p4 MHNC 13872 2.97 2.84 – – – m1 MHNC 13872 3.58 – 3.03 2.67 – root C MHNC 13868 3.94 2.45 – – – P1 MHNC 13868 1.99 1.40 – – – P2 MHNC 13868 2.66 2.03 – – – P3 MHNC 13868 3.35 3.56 – – – P4 MHNC 13868 3.17 3.98 – – – Height of Maxilla at level of infraorbital foramen Maxilla MHNC 13868 – – – – 12.14 M1 MHNC 13876 3.36 4.47 – – – M2 MHNC 13876 3.74 6.11 – – – Tiuclaenus minutus M1 MHNC 13879 2.20 3.10 – – – M2 MHNC 13879 2.23 3.45 – – – M3 MHNC 13879 1.54 2.87 – – – Length M1-3 M1-3 MHNC 13879 – – – – 5.86 Tiuclaenus robustus m2 MHNC 13875 3.64 – 3.04 2.64 – m3 MHNC 13875 3.71 – 2.52 2.14 – Pucanodus gagnieri m2 MHNC 13869 2.92 – 2.47 2.28 – m3 MHNC 13869 3.23 – 2.84 1.99 – table 6 . — Dental loci known so far in the Tiupampa kollpaniines. Abbreviations: al, alveolus; low, lower teeth; rt, roots; T, tooth; up, upper teeth. New data from the specimens described in this paper are marked in red. I1 I2 I3 C P1 P2 P3 P4 M1M2M3 Molinodus suarezi up – – – – – – T T T T T low al al al T T T T T T T T Simoclaenus sylvaticus up – – – rt T T T T T T T low – – – – al rt rt T T T T Tiuclaenus minutus up – – – – – – – – T T T low – Tal Tal T T T T T T Tiuclaenus cotasi up – – – – – T T T T T T low – – – – – – T T T T T Tiuclaenus robustus up – – – – – – T T T T T low – – – – – T– – T T T Pucanodus gagnieri up – – – – – – T T T T T low al al al T rt T T T T T T Andinodus boliviensis up – – – – – – – – – – – low – – – – – – – – – T T 860 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. of the protocone of the premolars. In contrast, other Tiupampa kollpaniines (Tiucalenus and Pucanodus) more closely resemble in this respect the North American mioclaenids and early South American didolodontids and litopterns. Among other South American Native Ungulates (SANU) the early notoungulate Henricosbornia lophodonta (MACN 10808) and the basal astrapothere Eoastrapostylops riolorense also have a P3 with a distinctly smaller protocone than on P4. The P2 of E. riolorense (P2 unknown in H. lophodonta) lacks a protoconal bulge as in Tiuclaenus. protocone, Hypocone, and pseudoHypocone One of the new specimens of Molinodus suarezi described here, is a maxilla, which bears the three molars (Fig. 5). Although the labial edge of M1-2 is damaged, the most interesting feature of this specimen rests on the protocone of these teeth. This cusp is clearly elongated anteroposteriorly (the wear facets are oval-shaped) and on M2 the apex of the cusp is clearly pinched transversely, individualizing an anterior and a posterior lobe, the latter being smaller than the former (Fig. 5). This condition had been already observed on Molinodus by Muizon & Cifelli (2000: fig. 2A) on the specimen MHNC 8280. This incipient process of duplication of the protocone is tentatively regarded here as an incipient process of individualization of a hypocone. The hypocone is a newly acquired cusp of the tribosphenic molar, which tends to enlarge the occlusal area of the tooth distolingually. The acquisition of a hypoconal cusp in mammals is a heavily homoplastic apomorphy, which occurred at least 20 times in mammalian evolution (Hunter & Jernvall 1995). It is most commonly achieved in two main different ways (Hershkovitz 1971; Hunter & Jernvall 1995; Jernvall 1995; Gheerbrant et al. 2016): 1) The postcingulum develops a lingual cusp, which increases in size and reaches that of the protocone. It is the hypocone of Hershkovitz (1971) also frequently called “true” hypocone (e.g., Stehlin 1916; Gregory 1922; Voruz 1970; Hunter & Jernvall 1995; Anemone et al. 2012). In this case, the increase in size of the postcingulum features a transitional stage called hypocone shelf (Jernvall 1995). A “true” hypocone (postcingulum-derived hypocone) has been documented, for example in phenacodontids and perissodactyls (Gheerbrant et al. 2016; but see below for a possible alternative interpretation of the perissodactyls hypocone), in the South American didolodont “condylarths” Escribania (Gelfo et al. 2007), Ricardocifellia, Didolodus, in the protolipternid litopterns Miguelsoria, Protolipterna, Asmithwoodwardia, and in, at least, some other litopterns (e.g., Licaphrium, Picturotherium), (personal observations). In these taxa, the hypocone does not represent a posterior extension of the protocone. The postprotocrista still connects the protocone to the metaconule and the latter has no connection with the hypocone thus demonstrating that the hypocone is actually an enlarged post-cingular cusp, and therefore a true hypocone. Furthermore, the protocone and the hypocone are fully separated up to the base of the cusps, thus retaining the initial separation of the postcingulum and the protocone. 2) The second frequently observed pattern of formation of a hypocone is not a cusp neoformation but is achieved by a distolingual migration of the metaconule, which increases in size posterior to the protocone. This type of hypocone (metaconule-derived hypocone) has been called pseudohypocone (e.g., Ladevèze et al. 2010; Gheerbrant et al. 2016). This condition is observed for instance in Paenungulatomorpha (Gheerbrant et al. 2016), Artiodactyla (Hunter & Jernvall 1995), and pleuraspidotheriid “condylarths” (Ladevèze et al. 2010). If one designates a postcingulum derived (see above) as the “true” hypocone, following for instance Stehlin (1916), Gregory (1922), and Butler 2000, then functional hypocones of other origins are de facto pseudohypocones. The term “pseudohypocone” has been created by Stehlin (1916) to designate the cusp arising from a postprotocone fold on the posterior edge of the protocone (the “Nannopithex fold”), possibly homologous to part of the postprotocrista (Godinot 2007) (but see Hershkovitz [1977] and Anemone et al. [2012] for a different interpretation). This third pattern of formation of a functional hypocone is present in notharctine primates (e.g., Gregory 1920, 1922; Gazin 1958; Butler 2000; Anemone et al. 2012). All other primates have a true hypocone (i.e. postcingulum-derived). A pseudohypocone derived from the posterior extension of the protocone posterior slope has also been documented (in addition to notharctines) for Dinocerata (Wheeler 1961; Hunter & Jernvall 1995; Jernvall 1995). In these taxa, however, the pseudohypocone results from a budding of the posterior slope of the protocone rather than from a duplication of the protocone. Based on these considerations, three main types of functional hypocones formation are distinguished here and designated as follows (though other modes may exist; Hunter & Jernvall 1995): the postcingulum-derived “true” hypocone, the metaconular (M) pseudohypocone and the protocone-derived pseudohypocone, either derived from a posterior extension of the protocone posterior slope (PPSD) or derived from a duplication of the whole protocone (PDD). The condition observed in Molinodus suarezi foreshadows the protocone-duplication-derived (PDD) pattern of individualization of a pseudohypocone. Such a PDD pseudohypocone may also be present in Raulvaccia peligrensis (from the early Palaeocene of Punta Peligro). In this taxon (Gelfo 2007: fig. 2C, D), the distolingual cusp is still connate to the table 7 . — Distribution of kollpaniine specimens from Tiupampa according to taxa. Number of specimens Total number Upper jaws Isolated upper teeth Lower jaws Isolated lower teeth Tiuclaenus cotasi 25 1 7 10 7 Molinodus suarezi 21 3 5 9 4 Tiuclaenus minutus 15 5 4 4 2 Pucanodus gagneri 15 3 8 4 – Tiuclaenus robustus 6 1 2 2 1 Simoclaenus sylvaticus 5 3 – 2 – Andinodus boliviensis 2 – – 2 – 861 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) distal edge of the protocone (the tooth being triangular and not quadrate) and is well separated from the distal cingulum (which bears a distinct small lingual cusp, indicating its lingual end – see Fig. 12 and Gelfo 2007: fig. 2C, D) and much higher, a condition which suggests a process of duplication from the protocone similar to that observed in Molinodus. The condition of Raulvacia is more similar to what is observed in Molinodus than to that of the M2 of Escribania (MLP 90-II12-63) figured by (Gelfo et al. 2007: fig. 4e), in which the two cusps appear to be well individualized, separated by a deep lingual furrow (absent in Raulvacia and Molinodus), and not connate all along their length in contrast to the condition observed in Molinodus. Furthermore, in Raulvacia, the cusp distal and connate to the protocone (pseudohypocone), is still attached to the metaconule by a postprotocrista, which would suggest that it originates from a duplication of the protocone and not from the postcingulum. This condition further suggests that the distolingual cusp of the M2 of Raulvacia actually represents a PDD pseudohypocone (Fig. 12). Such a condition is not observed on the M2 of Escribania mentioned above. Furthermore, the latter tooth is associated (on a maxillary fragment) to an M3, which presents a wellindividualized protocone and no well-defined hypocone but a distally inflated postcingulum whose lingual cusp is clearly lower than the protocone. This condition would indicate that the increase of the crushing surface of the tooth, in Escribania, is achieved through the postcingulum rather than through a duplication of the protocone. An almost identical condition is also observed on MNRJ 1462-V a maxilla fragment of Ricardocifellia protocenica bearing right M2-3. On this specimen (whose teeth are better preserved than those of Raulvacia peligrensis considered above), M2 has a distinctly postcingulum-derived-hypocone (with a protocone connected to metaconule by the postprotocrista, and a hypocone not connected to metaconule), whereas M3 has no hypocone but a thickened postcingulum. It is noteworthy, however, that Raulvaccia differs from Molinodus (and Lamegoia; see below) in the lingual edge of the postcingulum, which reaches the apex of the cusp connate to the protocone, whereas, in the latter two genera, it remains at the base of the cusp. The oval-shaped morphology observed on the protocone of the M2 referred to Simoclaenus sylvaticus described above (Fig. 9), probably indicates, in this taxon, a pattern similar to that of Molinodus and, possibly, Raulvacia. As mentioned by Muizon & Cifelli (2000: 73), a condition indicating a pattern similar to that of Molinodus, but more emphasized, is present on an unworn M2 referred by Paula Couto (1952a: pl. 32, fig. 7) to Lamegoia conodonta (paratype, MNRJ 1465-V). On this specimen (Fig. 13B), the protocone is partly divided into two cusps, which are confluent on most of their height and whose apices only are fully separated. The mesial cusp is connected to the paraconule by a short oblique pseudohypocone = duplication of the protocone postcingulum postprotocrista metaconule metacone lingual cusp of precingulum pr ecingulum paracone paraconule preprotocrista lingual cusp of postcingulum protocone fig. 12. — Raulvaccia peligrensis: left M2 (cast of MLP 90-II-12-70) in occlusal view. Comment: we tentatively refer this tooth to an M2 (contra Gelfo 2007, who refers it to an M1?) because of the mesiolabial position of the paracone (as related to metacone), which provides to the tooth a distinct asymmetrical morphology as is observed on the M2s of Molinodus and Simoclaenus but not on the M1s of these taxa. Scale bar: 5 mm. 862 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. preprotocrista and the posterior cusp is connected to the metaconule by a short transverse crista, which we interpret as the postprotocrista. The postcingulum presents a small lingual cusp which contacts both the distal protoconal cusp and the metaconule at their base. The distal cusp of the protocone of the M2 of Lamegoia mentioned above is regarded here as a PDD pseudohypocone in process of individualization. The other molar referred by Paula Couto (1952a: pl. 32, fig. 8), (paratype MNRJ 1464-V) bears a true hypocone, which is clearly the enlargement of the lingual cusp of the postcingulum (Fig. 13C). This hypocone is not connected to the metaconule and the postprotocrista links the metaconule to the protocone. In contrast, the hypocone of MNRJ 1465-V is connected to the protocone by an anteroposteriorly oriented short crista (the entocrista of Hershkovitz 1971), whereas such a structure is absent in MNRJ 1464-V. We therefore conclude that the two upper molars referred by Paula Couto (1952a) to Lamegoia conodonta, exhibit a different pattern of formation of a hypocone, and are probably not referable to the same taxon. Now, because the holotype of L. conodonta is an isolated lower molar (Fig. 13A), it is unclear what tooth actually represents an upper molar of L. conodonta, if any. However, the Molinodus-like molar (MNRJ 1465-V) presents a finely wrinkled enamel and its cristae are granulous as if they were formed of adjoined little cuspules (Fig. 13B). This morphology perfectly matches the condition observed on the lower molar of the holotype but distinctly differs from the other upper molar (with a true hypocone). Furthermore, as noted by Jernvall (1995), the development of a hypocone (distolingual cusp) and the consecutive squaring of the upper molars is associated to a reduction of the paraconid (mesiolingual cusp). Because the paraconid of the holotype of Lamegoia conodonta is not reduced (in contrast to the condition in Miguelsoria, which has squared upper molars with a large true hypocone) this condition could be related to a lesser development of a posterolingual cusp (i.e. a PDD pseudohypocone still connate to the protocone). Therefore, we tentatively refer the molar with a PDD pseudohypocone (MNRJ 1465-V) to the holotype of L. conodonta. The other molar (MNRJ 1464-V), with a true postcingulum-derived hypocone better resembles a large didolodontid close to Ricardocifellia (personal observations). The upper molar (M2, MNRJ 1465-V) referred here to Lamegoia conodonta (Fig. 13B) also resembles the M2s of Molinodus and Simoclaenus in its asymmetrical (roughly triangular) outline as mentioned by Muizon & Cifelli (2000: 73). This morphology is in part due to the size and position of the paracone, which is larger than the metacone and placed more labially. Interestingly, the M2 of L. conodonta bears a small cuspule between the paraconule and the small parastyle. A similar cuspule is also observed on the unworn M2 of Molinodus suarezi (Muizon & Cifelli 2000: fig. 2A) and also on the new M2 of Simoclaenus sylvaticus described above (Fig. 9). Such a cuspule is not observed or is barely discernible on the other South American “condylarths” or protolipternids. An asymmetrical, roughly triangular, outline of the M2 is also observed in Raulvaccia from Punta Peligro (Gelfo 2007: fig. 4C). PDD pseudohypocone lingual cusp of postcingulum protocone postprotocrista metaconule metacone precingulum paracone entocrista paraconule preprotocrista lingual cusp of precingulum postcingulum paracone metacone metaconul e postcingulum hypocone = lingual cusp of postcingulum postprotocrista lingual cusp of precingulum protocone preprotocrista paraconule precingulum paraconid metaconid protoconid hypoconid hypoconulid entoconid ABC parastyle small cuspule parastyle fig. 13. — A, B, Lamegoia conodonta; C, didolodontidae indet.; A, occlusal view of a left m2 of Lamegoia conodonta (cast of holotype MNRJ 1463-V); B, occlusal view of a right M2 (reversed) of Lamegoia conodonta (cast of MNRJ 1465-V); C, occlusal view of a left M2 (cast of MNRJ 1464-V) of and undetermined didolodont (referred by Paula Couto [1952a] to L. conodonta). Scale bar: 5 mm. 863 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) We have not observed any other M2 of “condylarths” in South America which matches those aspects of the M2 of Molinodus and Simoclaenus as well as those of Lamegoia conodonta and Raulvaccia peligrensis. Furthermore, the m2 (holotype) of L. conodonta (Fig. 13A) resembles the m2 of Molinodus (Figs 4; 5) in its large paraconid, probably related to the posteriorly displaced metaconid and to the obliquity of the protocristid. This condition is not present in Didolodus, Asmithwoodwardia, and Protolipterna; it is present, to a lesser extent, in Ricardocifellia, Ernestokokenia, and Miguelsoria. Among other SANUs, a pseudohypocone resulting from the duplication of the protocone may also be present in notoungulates. The oldest notoungulate record is represented by an isolated incomplete upper molar from Tiupampa (Muizon et al. 1984; Muizon 1992), (Fig. 14A). The tooth, although damaged, distinctly presents the characteristic features of the basal notoungulate pattern illustrated by the upper molar of cf. Henricosbornia (MNHN.F.CAS2714; Fig. 14B) (Simpson 1948; Cifelli 1993; Billet 2011). On both teeth, the protoloph and metaloph respectively bear at their lingual edges the protocone and the pseudohypocone. We regard the latter as a pseudohypocone for the following reasons: 1) because of the presence of a crest (postprotocrista) that connects it to the metaconule (worn off on the Tiupampa specimen), embedded within the metaloph; 2) because of the position of the lingual edge of the postcingulum, which remains at base of the pseudohypocone not presenting any lingual cusp nor any connection to the pseudhypocone; and 3) because of the lack of crista connecting the protocone to the metaconule (Fig. 14B). Similar observations were also made on other early diverging notoungulates such as Colbertia and Simpsonotus (pers. obs.). Because of this configuration, it is unlikely that the posterolingual cusp of the notoungulate molar could be derived from the increase in size of the lingual end of the postcingulum as is observed for a true hypocone (e.g., in protolipternids, didolodontids, phenacodontids) (contra Hunter & Jernvall 1995: table 1, who identified the hypocone of notoungulates as postcingulum-derived). In both figured notoungulate specimens, the protocone and pseudohypocone are linked by a distinct entocrista, a condition that is never as pronounced in didolodontids and litopterns. If this interpretation is correct, the molar structure of Molinodus (as well as that of Lamegoia) would more resemble, in this respect, the notoungulate than the litoptern pattern. This hypothesis may favor an inclusion of the Notoungulata in the Panameriungulata in a position closer to the Kollpaniinae than to the Litopterna. Such a position for notoungulates has already been suggested by Cifelli (1993), who stated that they could readily have derived from a Tiuclaenus-like ancestral morphotype. Furthermore, Cifelli's statement has been reinforced by the similarities between the tarsus of Tiuclaenus and early diverging notoungulates (Muizon et al. 1998; Muizon & Cifelli 2000). Therefore, the assumed similar pattern of pseudohypocone formation in some kollpaniines (Molinodus, Simoclaenus), Lamegoia, and, possibly, postcingulum precingulum pseudohypocone protocone protoloph metaloph entocrista lingual cingular cusps A postcingulum precingulum pseudohypocone protocone postprotocrista entocrista lingual cingular cusps metaconule metacone paracone B metacone protoloph preprotocrista paraconule metaloph incipient crista metastyle parastyle fig. 14. — Notoungulates left upper molars (M1 or M2) in occlusal view: A, MNHN VIL 123, the only notoungulate tooth from Tiupampa (cf. Henricosborniidae); B, MNHN.F.CAS2714, cf. Henricosbornia. Scale bar: 5 mm. 870 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. Acknowledgements The specimens described here have been collected during field expeditions funded by the National Geographic Society (grants 6296/98, 7109/01, 9394/13); Funds for fieldwork were also provided by the Muséum national d’Histoire naturelle (Paris, France), in 2006 and 2012. Fossil collecting was carried out under the auspices of research agreements between the Museo de Historia Natural Alcide d’Orbigny of Cochabamba (Bolivia) and the Muséum national d’Histoire naturelle (France). All the specimens collected are the property of the MHNC and were provided on loan to the MNHN for curation and publication. Field expeditions have benefited of logistical support from the IDR (Institut de Recherche pour le Développement) in Bolivia. We thank our Bolivian colleague Ricardo Céspedes-Paz, for his collaboration and logistic support during all the field seasons. Special thanks are due to Richard Cifelli (Oklahoma Museum of Natural History) and Javier Gelfo (Museo de La Plata) for providing cast of didolodontids and protolipternids. This work has benefited from fruitful discussion with Constance Bronnert, Emmanuel Gheerbrant, Marc Godinot, Grégoire Métais (CR2P, CNRS, MNHN, Sorbonne Université). Special thanks are due to Javier Gelfo and Lilian Bergqvist, whose careful reviews allowed for substantial improvement of our manuscript. Photographs were made by Philippe Loubry and Lilian Cazes. REFERENCES aneMone r. l., sKInner M. M. & dIrKs W. 2012. — Are there two distinct types of hypocone in Eocene primates? The ‘pseudohypocone’ of notharctines revisited. Palaeontologia electronica 15 (3): 26A, 13 p. arcHIbald J. d. & averIanov a. o. 2005. — Mammalian faunal succession in the Cretaceous of the Kyzylkum Desert. Journal of Mammalian Evolution 12: 9-22. https://doi.org/10.1007/ s10914-005-4867-3 asHer r. & Helgen K. 2010. Nomenclature and placental mammal phylogeny. BMC Evolutionary Biology 10:102-110. https:// doi.org/10.1186/1471-2148-10-102 b aI b., W ang y-Q., l I Q., W ang H.-b., M ao F.-y., g ong y.-X. & Meng J. 2018. — Biostratigraphy and Diversity of Paleogene Perissodactyls from the Erlian Basin of Inner Mongolia, China. American Museum Novitates 3914: 1-60. https://doi. org/10.1206/3914.1 baJpaI s., Kapur v. v., tHeWIssen J. g. M., das d. p. & tIWarI b. n. 2006. — New early Eocene cambaythere (Perissodactyla, Mammalia) from the Vastan Lignite Mine (Gujarat, India) and an evaluation of cambaythere relationships. Journal of the Palaeontological Society of India 51 (1): 101-110. bIllet g. 2011. — Phylogeny of the Notoungulata (Mammalia) based on cranial and dental characters. Journal of Systematic Palaeontology 9 (4): 481-497. https://doi.org/10.1080/14772 019.2010.528456 bronnert c., gHeerbrant e., godInot M. & MetaIs g. 2017. — A primitive perissodactyl (Mammalia) from the early Eocene of Le Quesnoy (MP7, France). Historical Biology 30 (1-2): 237-250. https://doi.org/10.1080/08912963.2017.1341502 bucKley M. 2015. — Ancient collagen reveals evolutionary history of the endemic South American ‘ungulates’. Proceedings of the Royal Society of London B: Biological Sciences 282 (1806): 20142671. https://doi.org/10.1098/rspb.2014.2671 butler p. 2000. — The evolution of tooth shape and tooth function in primates, in teaFord M., sMItH M. & Ferguson M. (eds), Development, Function and Evolution of Teeth. Cambridge University Press, Cambridge: 201-211. https://doi.org/10.1017/ CBO9780511542626.014 carter K. e. & WortHIngton s. 2016. — The evolution of anthropoid molar proportions. BMC Evolutionary Biology 16: 110. https://doi.org/10.1186/s12862-016-0673-5 cIFellI r. l. 1983. — The origin and affinities of the South American Condylarthra and early Tertiary Litopterna (Mammalia). American Museum Novitates 2772: 1-49. http://hdl.handle.net/2246/5256 c IFellI r. l. 1993. — The phylogeny of the native South American ungulates, in szalay F. s., novaceK M. J. & McKenna M. C. (eds), Mammal Phylogeny. Vol. 2. Placentals. Springer Verlag, New York: 195-216. clyde W. c., WIlF p., IglesIas a., slIngerland r. l., barnuM t., bIJl p. K., braloWer t. J., brInKHuIs H., coMer e. e., H uber b. t., I bañez -M eJIa M., J IcHa b. r., K rause J. M., scHuetH J. d., sInger b. s., raIgeMborn M. s, scHMItz M. d., sluIJs a. & zaMaloa M. d. c. 2014. — New age constraints for the Salamanca Formation and lower Río Chico Group in the western San Jorge Basin, Patagonia, Argentina: Implications for Cretaceous-Paleogene extinction recovery and land mammal age correlations. Geological Society of America Bulletin 126: 289-306. https://doi.org/10.1130/B30915.1 cooper l. n., seIFFert e. r., cleMentz M., Madar s. I., baJpaI s., HussaIn s. t. & tHeWIssen J. g. M. 2014. — Anthracobunids from the Middle Eocene of India and Pakistan are stem Perissodactyls. PLoS ONE 9 (10): e109232. https://10.1371/ journal.pone.0109232 evans H. e. & de laHunta a. 2013. — Miller’s Anatomy of the Dog. Saunders, St Louis, 850 p. FoX r. c. 2015. — A revision of the Late Cretaceous-Paleocene eutherian mammal Cimolestes Marsh, 1889. Canadian Journal of Earth Sciences 52: 1137-1149. https://doi.org/10.1139/cjes2015-0113 gazIn c. l. 1958. — A review of the Middle and upper Eocene primates of North America. Smithsonian Miscellaneous Collections 136 (1): 1-112. https://biodiversitylibrary.org/page/26247219 g elFo J. n. 2004. — A new South American mioclaenid (Mammalia, Ungulatomorpha) from the Tertiary of Patagonia, Argentina. Ameghiniana 41: 475-484. gelFo J. n. 2007. — The ‘condylarth’ Raulvaccia peligrensis (Mammalia, Didolodontidae) from the Paleocene of Patagonia, Argentina. Journal of Vertebrate Paleontology 27: 651-660. https://doi. org/10.1671/0272-4634(2007)27[651:TCRPMD]2.0.CO;2 gelFo J. n. & sIgé b. 2011. — A new didolodontid mammal from the late Paleoceneearliest Eocene of Laguna Umayo, Peru. Acta Paleontologica Polonica 54 (4): 665-678. https://doi. org/10.4202/app.2010.0067 gelFo J. n., goIn F. J., Woodburne M. o. & MuIzon c. de 2009. — Biochronological relationships of the earliest South American Paleogene mammalian faunas. Palaeontology 52 (1): 251-269. https://doi.org/10.1111/j.1475-4983.2008.00835.x gelFo J. n., ortIz-JaureguIzar e. & rougIer g. W. 2007. — New remains and species of the “Condylarth” genus Escribania (Mammalia, Didolodontidae) from the Paleocene of Patagonia, Argentina. Transactions of the Royal Society of Edimburgh, Earth and Environmental Sciences 98: 127-138. https://doi.org/10.1017/ S1755691007006081 gHeerbrant e., aMagHzaz M., bouya b., goussard F., letenneur c. 2014. — Ocepeia (Middle Paleocene of Morocco): the oldest skull of an afrotherian mammal. PLoS ONE 9: e89739. https://doi.org/10.1371/journal.pone.0089739 gHeerbrant e., FIlIppo a. & scHMItt a. 2016. — Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco. PLoS ONE 11 (7): e0157556. https://doi.org/10.1371/journal.pone.0157556 871 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) godInot M. 2007. — Primate origins: a reappraisal of historical data favoring tupaiid affinities, in ravosa M. J. & dagosto M. (eds), Primates Origins: Adaptations and Evolution. Springer verlag, New York: 83-142. https://doi.org/10.1007/978-0-38733507-0_4 goIn F. J., pascual r., teJedor M., gelFo J. n., Woodburne M., case J., reguero M., bond M., cIone a., udrIzar sautHIer d., balarIno l., scasso r., MedIna F. a. & ubaldón M. c. 2006. — The earliest Tertiary therian mammal from South America. Journal of Vertebrate Paleontology 26 (2): 505-510. https:// doi.org/10.1671/0272-4634(2006)26[505:TETTMF]2.0.CO;2 goMes-rodrIgues e., Herrel a. & bIllet g. 2017. — Ontogenetic and life history trait changes associated with convergent ecological specializations in extinct ungulate mammals. Proceeding of the national Academy of Science of the United States of America https://doi.org/10.1073/pnas.1614029114 gregory W. K. 1920. — On the structure and relations of Notharctus, an American Eocene primate. Memoirs of the American Museum of Natural History, New series, Volume 3 (2): 1-243. https:// biodiversitylibrary.org/item/165714 gregory W. K. 1922. — The origin and evolution of the human dentition. Williams and Wilkins, Baltimore, xviii p., 548 p., 15 pls. HallIday t. J. d. & gosWaMI a. 2013. — Testing the inhibitory cascade model in Mesozoic and Cenozoic mammaliaformes. BMC Evolutionary Biology 13 (79): 1-11. https://doi.org/10.1186/14712148-13-79 HallIday t. J., upcHurcH p. & gosWaMI a. 2017. — Resolving the relationships of Paleocene placental mammals. Biological Reviews 92 (1): 521-550. https://doi.org/10.1111/brv.12242 H ersHKovItz p. 1971. — Basic crown patterns and cusp homologies of mammalian teeth, in daHlberg A. A. (ed.), Dental Morphology and Evolution. University of Chicago Press, Chicago: 95-150. HersHKovItz p. 1977. — Living New World Monkeys (Platyrrhini), with an Introduction to Primates. Volume 1. University of Chicago Press, Chicago, 1132 p. HersHKovItz p. 1982. — The staggered marsupial lower third incisor (i3). Geobios, mémoire spécial, 6: 191-200. https://doi. org/10.1016/S0016-6995(82)80113-7 HersHKovItz p. 1995. — The staggered marsupial lower incisor: hallmark of cohort Didelphimorphia. and description of a new genus and species with staggered i3 from the Albian (Lower Cretaceous) of Texas. Bonner Zoologische Beitrage 45 (3-4): 153-169. https://biodiversitylibrary.org/page/44799597 H olbrooK l. 2015. — The identity and homology of the postprotocrista and its role in molarization of upper premolars of Perissodactyla (Mammalia). Journal of Mammalian Evolution 22: 259-269. https://doi.org/10.1007/s10914-014-9276-3 H ooKer J. J. 1989. — Character polarity in early perissodactyls and their significance for Hyracotherium and intraordinal relationships, in protHero d. r. & scHocH R. M. (eds), The Evolution of Perissodactyls. Oxford University Press, New York: 79-101. HooKer J. J. 1994. — The beginning of the equoid radiation. Zoological Journal of the Linnean Society 112: 29-63. https://doi. org/10.1111/j.1096-3642.1994.tb00311.x HooKer J. J. & russell d. e. 2012. — Early Palaeogene Louisinidae (Macroscelidea, Mammalia), their relationships and north European diversity. Zoological Journal of the Linnean Society 164 (4): 856-936. https://doi.org/10.1111/j.1096-3642.2011.00787.x Hunter J. p. & Jernvall J. 1995. — The hypocone as a key in mammalian evolution. Proceeding of the National Academy of Sci - ences of the United States of America 92: 10718-10722. https:// doi.org/10.1073/pnas.92.23.10718 Jernvall J. 1995. — Mammalian molar cusp pattern: developmental mechanisms of diversity. Acta Zoologica Fennica 198: 1-61. KavanagH K. d., evans a. r. & Jernvall J. 2007. — Predicting evolutionary patterns of mammalian teeth from development. Nature 449: 427-432. https://doi.org/10.1038/nature06153 KIelan-JaWoroWsKa z. 1981. — Evolution of the therian mammals in the Late Cretaceous of Asia. Part IV. Skull structure of Kennalestes and Asioryctes. Palaeontologia Polonica 42: 25-78. K Ielan -J aWoroWsKa z. & d asHzeveg d. 1989. — Eutherian mam - mals from the Early Cretaceous of Mongolia. Zoologica Scripta 18 (2): 347-355. https://doi.org/10.1111/j.1463-6409.1989.tb00460.x K Itts d. b. 1956. — American Hyracotherium (Perissodactyla, Equidae). Bulletin of the American Museum of Natural History 110 (1): 1-60. KraMartz a. g. & bond M. 2005. — Los litopterna (Mammalia) de la Formación Pinturas, Mioceno Temprano-Medio de Patagonia. Ameghiniana 42 (3): 611-625. ladevèze s., MIssIaen p. & sMItH t. 2010. — First skull of Orthaspidotherium edwarsi (Mammalia, “Condylarthra”) from the late Paleocene of Berru (France) and phylogenetic affinities of the enigmatic European family Pleuraspidotheriidae. Journal of Vertebrate Paleontology 30 (5): 1559-1578. https://doi.org/10. 1080/02724634.2010.501440 luo z.-X., yuan c.-X., Meng Q.-J. & JI Q. 2011. — A Jurassic eutherian mammal and divergence of marsupials and placentals. Nature 476: 442-445. https://doi.org/10.1038/nature10291 MarsHall l. g., seMpere t. & butler r. F. 1997. — Chronostratigraphy of the mammal-bearing Palaeocene of South America. Journal of South American Earth Sciences 10: 49-70. https://doi. org/10.1016/S0895-9811(97)00005-9 MuIzon c. de 1992. — La fauna de mamíferos de Tiupampa (Paleoceno inferior, Formacíon Santa Lucía) Bolivia. Revista Técnica de Yacimientos Petrolíferos Fiscales de Bolivia 12 (3-4): 575-624. MuIzon c. de & cIFellI r. l. 2000. — The “condylarths” (archaic Ungulata, Mammalia) from the early Palaeocene of Tiupampa (Bolivia): implications on the origin of the South American ungulates. Geodiversitas 22 (1): 47-150. MuIzon c. de & MarsHall l. g. 1987 — Le plus ancien Condylarthre (Mammalia) sud-américain (Crétacé supérieur, Bolivie). Compte Rendus hebdomadaires des Séances de l’Académie des Sciences 304: 771-774. M uIzon c. de & M arsHall l. g. 1991. — Nouveaux Condylarthres du Paléocène inférieur de Tiupampa (Bolivie). Bulletin du Muséum national d’Histoire naturelle, section C, Sciences de la Terre, 4 ème série, 13: 201-225. https://biodiversitylibrary.org/ page/55803145 M uIzon c. de , c IFellI r. l. & b ergQvIst l. p. 1998. — Eutherian tarsals from the early Paleocene of Bolivia. Journal of Vertebrate Paleontology 18: 655-663. https://doi.org/10.1080/02724634. 1998.10011092 MuIzon c. de, MarsHall l. g. & sIgé b. 1984. — The mammal fauna from the El Molino Formation (Late Cretaceous, Maestrichtian) at Tiupampa South Central Bolivia. Bulletin du Muséum national d’Histoire naturelle, section C, Sciences de la Terre, 4ème série, 6 (4): 327-351. https://biodiversitylibrary.org/ page/55710289 MuIzon c. de, bIllet g., argot c., ladevèze s. & goussard F. 2015. — Alcidedorbignya inopinata, a basal pantodont (Eutheria, Mammalia) from the early Palaeocene of Bolivia: anatomy, phylogeny, and palaeobiology. Geodiversitas 37 (4): 397-634. https://doi.org/10.5252/g2015n4a1 MuIzon c. de, ladevèze s., selva c., vIgnaud r. & goussard F. 2018. — Allqokirus australis (Sparassodonta, Metatheria) from the early Palaeocene of Tiupampa (Bolivia) and the rise of the metatherian carnivorous radiation in South America. Geodi - versitas 40 (16): 363-459. https://doi.org/10.5252/geodiversitas2018v40a16. http://geodiversitas.com/40/16 nessov l. a., arcHIbald J. d. & KIelan-JaWoroWsKa z. 1998. — Ungulate-like mammals from the Late Cretaceous of Uzbekistan and a phylogenetic analysis of Ungulatomorpha. Bulletin of the Carnegie Museum of Natural History 34: 40-88. https:// biodiversitylibrary.org/page/52329844 pascual r., vucetIcH M. g. & Fernandez J. 1978. — Los primeros mamíferos (Notoungulata, Henricosborniidae) de la 872 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. Formación Mealla (Grupo Salta, Subgrupo Santa Bárbara). Sus implicancias filogenéticas, taxonómicas y cronológicas. Ameghiniana 15: 366-390. paula couto c. de 1952a. — Fossil mammals from the beginning of the Cenozoic in Brazil: Condylarthra, Litopterna, Xenungulata, and Astrapotheria. Bulletin of the American Museum of Natural History 99: 355-394. http://hdl.handle.net/2246/417 paula couto c. de 1952b. — Fossil mammals from the beginning of the Cenozoic in Brazil. Notoungulata. American Museum Novitates 1568:1-16. http://hdl.handle.net/2246/2390 polly p. d. 2007. — Evolutionary biology: development with a bite. Nature 449: 413-415. https://doi.org/10.1038/449413a rasband W. s. 1997-2018. — ImageJ, U. S. National Institutes of Health, Bethesda, Maryland, United States. https://imagej.nih.gov/ij/ rose K. d., HolbrooK l. t., rana r. s., KuMar K., Jones K. e., a Hrens H. e., M IssIaen p., s aHnI a. & s MItH t. 2014. — Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India. Nature Communication 5: 1-9. https://doi. org/10.1038/ncomms6570 sHelley s. l., WIllIaMson t. e. & brusatte s. l. 2018. — The osteology of Periptychus carinidens: A robust, ungulate-like placental mammal (Mammalia: Periptychidae) from the Paleocene of North America. PLoS ONE 13 (7): e0200132. https://doi. org/10.1371/journal.pone.0200132 sIMpson g. g. 1948. — The beginning of the age of mammals in South America. Part II. Bulletin of the American Museum of Natural History 91 (1): 1-232. http://hdl.handle.net/2246/1632 spraIn c. J., renne p. r., WIlson g. p. & cleMens W. a. 2015. — High-resolution chronostratigraphy of the terrestrial Cretaceous-Paleogene transition and recovery interval in the Hell Creek region, Montana. Geological Society of America Bulletin 127 (3-4): 393-409. https://doi.org/10.1130/B31076.1 sorIa M. F. 1987. — Estudio sobre los Astrapotheria (Mammalia) del Paleoceno y Eoceno. Parte I: Descripción de Eoastrapostylops riolorense Soria y Powell, 1982. Ameghiniana 24: 43-51. sorIa M. F. & poWell J. e. 1981. — Un primitivo Astrapotheria (Mammalia) y la edad de la Formación Río Loro, Provincia de Tucumán, República Argentina. Ameghiniana 18:155-168. steHlIn H. g. 1916. — Die Säugetiere des schweizerischen Eocaens. Critischer Catalog der materialien. Caenopithecus – Necrolemur – Microchoerus – Nannopithex – Anchomomys – Periconodon – Amphichiromys – Heterochiromys – Nachträge zu Adapis – Schlussbetrachtungen zu den Primaten. Abhandlungen Schweizerischen Paläontologischen Gesellschaft 41: 1299-1552. https://biodiversitylibrary.org/page/14836550 tHenIus e. 1989. — Zähne und Gebiß der Säugetiere, in nIetHaMMer J., scHlIeMann H., & starcK D. (eds), Handbook of Zoology. Volume 8. Mammalia, part 56. Walter de Gruyter, Berlin: 1-513. tHeWIssen J. g. M., russell d. e., gIngerIcH p. d. & HussaIn s. t. 1983. — A new dichobunid artiodactyl (Mammalia) from the Eocene of north-west Pakistan. Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen, Series B, 86 (2): 153-180. voruz c. 1970. — Origine des dents bilophodontes des Cercopithecoidea. Mammalia 34 (2): 269-293. https://doi.org/10.1515/ mamm.1970.34.2.269 WelKer F., collIns M. J., tHoMas J. a., Wadsley M., brace s. & c appellInI e., t urvey s. t., r eguero M., g elFo J. n., K raMarz a., burger J., tHoMas-oates J., asHFord d. a., asHton p. d., roWsell K., porter d. M., Kessler b., FIscHer r., baessMann c., Kaspar s., olsen J. v., KIley p., ellIott J. a., Kelstrup c. d., M ullIn v., H oFreIter M., W Illerslev e., H ublIn J.-J., orlando l., barnes I. & MacpHee r. d. e. 2015. — Ancient proteins resolve the evolutionary history of Darwin’s South American ungulates. Nature 522: 81-84. https://doi.org/10.1038/nature14249 Westbury M., baleKa s., barloW a., HartMann s., paIJMans J. l. a., KraMarz a., ForasIepI a. M., bond M., gelFo J. n., reguero M. a., lopez Mendoza p., taglIorettI M., scaglIa F, r InderKnecHt a., J ones W., a guIlar J. l., b Illet g., M uIzon c. de, MacpHee r. d. e. & HoFreIter M. 2017. — A mitogenomic timetree for Darwin’s “transitional” South American mammal, Macrauchenia patachonica. Nature Communications 8: 15951. https://doi.org/10.1038/ncomms15951 WHeeler W. H. 1961. — Revision of the Uintatheres. Peobody Museum of Natural History, Bulletin 14: 1-93. https://biodiversitylibrary.org/page/10600608 WIble J. r., novaceK M. J. & rougIer g. W. 2004. — New data on the skull and dentition in the Mongolian Cretaceous eutherian mammal Zalambdalestes. Bulletin of the American Museum of Natural History 281: 1-144. https://doi.org/10.1206/00030090(2004)281<0001:NDOTSA>2.0.CO;2 WIble J. r., rougIer g. W., novaceK M. J. & asHer r. J. 2009. — The eutherian mammal Maelestes gobiensis from the Late Cretaceous of Mongolia and the phylogeny of Cretaceous Eutheria. Bulletin of the American Museum of Natural History 327: 1-123. https://doi.org/10.1206/623.1 WIllIaMson t. e., WeIl a. & standHardt b. 2011. — Cimolestids (Mammalia) from the early Paleocene (Puercan) of New Mexico. Journal of Vertebrate Paleontology 31: 162-180. https:// doi.org/10.1080/02724634.2011.539649 WIlson g. p. 2013. — Mammals across the K/Pg boundary in Northeastern Montana, USA: Dental morphology and body-size patterns reveal extinction selectivity and immigrant-fueled ecospace filling. Paleobiology 39: 429-469. https://doi.org/10.1666/12041 W Ilson g. p. 2014. — Mammalian extinction, survival, and recovery dynamics across the Cretaceous-Paleogene boundary in Northeastern Montana, USA, in WIlson g. p., cleMens W. a., Horner J. r., & HartMan J. H. (eds), Through the End of the Cretaceous in the Type Locality of the Hell Creek Formation in Montana and Adjacent Areas. Geological Society of America, Special Paper 503: 365-392. https://doi.org/10.1130/2014.2503(15) WIlson l. a., sáncHez-vIllagra M. r., Madden r. H. & Kay r. F. 2012. — Testing a developmental model in the fossil record: molar proportions in South American ungulates. Paleobiology, 38 (2): 308-321. https://doi.org/10.1666/11001.1 Woodburne M. o., goIn F. J., bond M., carlInI a. a., gelFo J. n., lopez g. M., IglesIas a. & zIMIcz a. n. 2014a. — Paleogene land mammal faunas of South America; a response to climatic changes and indigenous floral diversity. Journal of mammalian Evolution 21 (1): 1-73. https://doi.org/10.1007/ s10914-012-9222-1 Woodburne M. o., goIn F. J., raIgeMborn M. s., HeIzler M., gelFo J. n. & olIveIra e. v. 2014b. — Revised timing of the South American Early Paleogene land mammal ages. Journal of South American Earth Sciences 54: 109-119. https:// doi.org/10.1016/j.jsames.2014.05.003 Submitted on 26 February 2019; accepted on 27 June 2019; published on 19 December 2019. 873 New remains of kollpaniine “condylarths” (Panameriungulata) from the early Palaeocene of Bolivia GEODIVERSITAS • 2019 • 41 (25) Taxa, specimens and references concerning the section “Molar proportions in kollpaniines and other ‘ungulates’” are indicated in Table 8. Alcidedorbignya inopinata MHNC 8372, 8399; Muizon & Marshall (1987); Muizon et al. (2015); Asioryctes and Kennalestes (Kielan-Jaworowska 1981; Wible et al. 2004); Asmithwoodwardia scotti, DGM 358-M; Paula Couto (1952a); Aspanlestes aptap, Nessov et al. (1998), Archibald & Averianov (2005); Baioconodon nordicum, cast of YPM-PU 14234; Colbertia magellanica, cast of DGM 357-M; Paula-Couto (1952b); Didolodus multicuspis, MACN 10690; Eoastrapostylops riolorense, Soria & Powell (1981), Soria (1987); Ernestokokenia cf. nitida, MNHN.F.CAS681, Muizon & Cifelli (2000); Escribania chubutensis, cast of (MLP 90-II-12-63), Gelfo et al. (2007); Hallensia louisis, Hooker (1994); Henricosbornia lophodonta, MACN 10808; cf. Henricosbornia, MNHN.F.CAS2714; Hyracotherium, Hooker (1994); Kulbeckia kulbecke, Wible et al. (2004, 2009); Lamegoia conodonta, casts of MNRJ 1463-V, MNRJ 1465-V, MNRJ 1464-V (specimen referred by Paula Couto [1952a] to Lamegoia conodonta but referred in this paper to a large didolodontid close to Ricardocifellia); Maiorana noctiluca, cast of YPM-PU 16667 and 14171; Miguelsoria parayirunhor, cast of MNRJ 4094-V; Cifelli (1983); Oxyprimus galadrielae (cast of YPM-PU 21015); Parazhelestes robustus (Nessov et al. 1998; Archibald & Averianov 2005); Pascualodus patagoniensis cast of MLP59-II-24-39, Gelfo (2004); Pliolophus quesnoyensis, MNHN.F.QNY2-2811, QNY1-482, QNY2-2880, QNY1-519, QNY2-2883, QNY2-2903, QNY2-2700, QNY2-2867, QNY2-2869, QNY1-382, QNY2-2900, QNY2-2705, QNY2-2854, QNY2-2707, QNY2-2815, QNY2-2808; Bronnert et al. (2017); Prokennalestes trofomovi and P. minor, Kielan-Jaworowska & Dashzeveg (1989); Promioclaenus acolytus, USNM 9575, AMNH 32728; Promioclaenus lemuroides, AMNH 4025; Propachynolophus levei, Hooker (1994); Protolipterna ellipsodontoides, MCT-1495M; Puercolestes simpsoni, Williamson et al. (2011); Raulvaccia peligrensis, cast of MLP 90-II-12-70; Gelfo (2007); Ricardocifellia protocenica, cast of DGM 908M, MNRJ 1462V; Paula Couto (1952a), Cifelli (1983); Simpsonotus praecursor cast of MLP 73-VII-3-11; Pascual et al. (1978); Zalambdalestes, Wible et al. (2004). appenDix 1. — Comparison taxon list, specimens and references. 874 GEODIVERSITAS • 2019 • 41 (25) Muizon C. de et al. Alcidedorbignya Muizon & Marshall, 1987; Alcidedorbignya inopinata Muizon & Marshall, 1987; Asioryctes Kielan-Jaworowska, 1975; Asmithwoodwardia Ameghino, 1901; Asmithwoodwardia scotti Paula Couto, 1952; Aspanlestes Nessov, 1985; Aspanlestes aptap Nessov, 1985; Baioconodon Gazin, 1941; Baioconodon nordicum (Jepsen, 1930); Colbertia Paula Couto, 1952; Colbertia magellanica Price & Paula Couto, 1950; Didolodus Ameghino, 1897; Didolodus multicuspis Ameghino, 1897; Eoastrapostylops Soria & Powell, 1981; Eoastrapostylops riolorense Soria & Powell, 1981; Ernestokokenia Ameghino, 1901; Ernestokokenia nítida Ameghino, 1911; Escribania Bonaparte Van Valen & Kramartz, 1993; Escribania chubutensis Van Valen & Kramartz, 1993; Hallensia Franzen & Haubold, 1986; Hallensia louisi Hooker, 1994; Henricosbornia Ameghino, 1901; Henricosbornia lophodonta Ameghino, 1901; Hyracotheriumi Owen, 1841; Kennalestes Kielan-Jaworowska, 1968; Kulbeckia Nessov, 1993; Kulbeckia kulbecke Nessov, 1993; Lamegoia Paula Couto, 1952; Lamegoia conodonta Paula Couto, 1952; Licaphrium Ameghino, 1887; Maiorana Van Valen, 1978; Maiorana noctiluca Van Valen, 1978; Miguelsoria Cifelli, 1983; Miguelsoria parayirunhor (Paula Couto, 1952); Oxyprimus Van Valen, 1978; Oxyprimus galadrielae Van Valen, 1978; Parazhelestes Nessov, 1993; Parazhelestes robustus Nessov, 1993; Pascualodus Gelfo, 2004; Pascualodus patagoniensis Gelfo, 2004; Picturotherium Kramartz & Bond, 2005; Pliolophus Owen, 1858; Pliolophus quesnoyensis Bronnert, Gheerbrant, Godinot & Métais, 2017; Prokennalestes Kielan-Jaworowska & Dashzeveg, 1989; Prokennalestes trofimovi Kielan-Jaworowska & Dashzeveg, 1989; P. minor Kielan-Jaworowska & Dashzeveg, 1989; Promioclaenus Trouessart, 1904; Promioclaenus acolytus Cope, 1882; P. lemuroides (Matthew, 1897); Propachynolophus Pomel, 1847; Propachynolophus levei Hooker, 1994; Protolipterna Cifelli, 1983; Protolipterna ellipsodontoides Cifelli, 1983; Puercolestes Reynolds, 1936; Puercolestes simpsoni Reynolds, 1936; Raulvaccia Van Valen & Kramartz, 1993; Raulvaccia peligrensis Van Valen & Kramartz, 1993; Ricardocifellia Mones, 2015; Ricardocifellia protocenica: Paula Couto (1952); Simpsonotus Pascual Vucetich & Fernandez, 1978; Simpsonotus praecursor Pascual, Vucetich & Fernandez, 1978; Zalambdalestes Kielan-Jaworowska, 1981. appenDix 2. — List of genus and species names cited in the text with authorship and year.