Biokovoamaurops, a new troglobitic genus of Amauropini (Coleoptera: Staphylinidae: Pselaphinae) from Biokovo Mt., Dalmatia

E-mail: [email protected] Biokovoamaurops, a new troglobitic genus of Amauropini (Coleoptera: Staphylinidae: Pselaphinae) from Biokovo Mt., Dalmatia Dragan Pavićević†1, Roman Ozimec2 1Krunska 15, 11 000 Belgrade, Serbia 2ADIPA: Society for Croatian Natural History Diversity Research & Conservation, Orehovečki ogranak 37, 10040 Zagreb, Croatia Biologia Serbica, 2025, 47: 0-0 DOI: 10.5281/zenodo.17849393 Summary. A new troglobitic genus, Biokovoamaurops, and the species B. nyx from the tribe Amauropini, are described and illustrated based on a female specimen collected in the Gradska špilja cave above Župa, on Mount Biokovo, Dalmatia. The new genus was found in the middle Dinaric region, opposite two closely related troglobitic genera Seracamaurops and Troglamaurops, which are distributed in the southern Dinaric region. Keywords: biospeleology, Croatia, Dinarides, Pselaphinae, taxonomy, new species. Accepted: 21 November 2025 INTRODUCTION In the Balkan Peninsula, the pselaphine tribe Amauropini is represented by seven genera (Amauropus Reitter, 1918, Paramaurops Jeannel, 1948, Protamaurops Müller, 1944, Pseudamaurops Jeannel, 1948, Seracamaurops Winkler, 1924, Troglamaurops Ganglbauer, 1903 and Zoufalia Reitter, 1918), with more than 50 described taxa (Nonveiller and Pavićević 2008; Hlaváč et al. 2008; Hlaváč et al. 2017; Lohaj et al. 2023; Pavićević et al. 2024a,b). Among members of the tribe Amauropini, only two genera, Troglamaurops and Seracamaurops are exclusively troglobionts, while representatives of the other above-mentioned genera can be collected in Mesovoid shallow substratum, under the stones at the entrance of the caves, in mould leaf litter, etc. During biospeleological research of the caves and pits of Mount Biokovo (Central Dalmatia, Central Dinarides) in 2004, one of us (R.O.) discovered a single pselaphine in the biological material collected in Gradska špilja cave, which in its habitus appeared to be strikingly similar to some smaller Seracamaurops, such as S. popovici Pavićević, Hlaváč & Lakota, 2008 or S. cadmei Pavićević & Ozimec 2013. However, other differences in morphology indicated that it belonged to an unknown new genus and species. For a period of almost 20 years, we have been searching for another specimen, especially a male that would help us determine the correct taxonomic position of this newly discovered genus among the Amauropini, but without success. Finally, we decided to publish the description of the new genus and species, due to the importance of this finding for the taxonomy of Amauropini, but also for the biogeography of the region itself. MATERIAL AND METHODS The specimen was studied in the laboratory using LEICA MZ 16 and WILD M 8 ZOOM stereomicroscopes. Specimen measurements were made for: total body length, head length, maximum head width, antennae length, pronotum length, Published online: 9 December 2025 D. Pavićević et R. Ozimec pronotum width, elytra length, and elytra width. Drawings of the habitus were made by our colleague, Momčilo Popović. Abbreviations and acronyms AL antennal length EL elytral length: linear distance measured along the suture from the elytral base to the apex EW maximum width of elytra HL head length: measured from the anterior margin of the clypeus to the neck constriction HR Croatia HW maximum head width LT Locus typicus NHGMV Natural-History Department of the State Museum of Varaždin city (GMV) (Croatia) PL pronotum length PW maximum pronotum width RH Relative humidity of the air ROC Roman Ozimec Collection, Varaždin, part of NHGMV (Croatia) Ta Temperature of the air TL total body length: measured from the apex of the mandibles to the apex of the last tergite Ts Temperature of the substrate TAXONOMY Biokovoamaurops, gen. n. Type species: Biokovoamaurops nyx gen. n., sp. n. Type material: Holotypus, female, Croatia, Middle Dalmatia, Split-Dalmatia County, Biokovo Mountain, Župa, Gradska špilja cave, 746 m a.s.l.; 25-05-2004, leg. P. Rade., Labelled: Inv. Nr. GMV 112635 (NHGMV). Diagnosis Amauropini with elongate head, frons with two depressions between antennal tubercules, vertex fovea deep; maxillary palpi small, III blade shaped, mandibles strong, frontal lobe transverse with widely rounded anterior margin; eyes completely atrophied without a trace of either ocular thorns or carinae. Temples strongly rounded and narrowed posteriorly, with long erect setae. Antennae relatively short, all segments elongate. Pronotum barrel-shaped, widest just behind the middle, median fovea elongated, and shallow, lateral fovea welldeveloped, deep. Elytra simple, elongated. Abdomen slightly wider than elytra, first visible tergit clearly wider then long. External striae diffuse with margin, internal striae very short. The legs long, meso-femora clubbed in the middle. Etymology The name of the genus is derived from the name of Mt. Biokovo, and the extension “amaurops” is associated with the genera and taxa belonging to Amauropini. Biokovoamaurops nyx gen. n., sp. n. Fig. 1 Type locality: same as for the genus Holotype: same as for the genus Paratypes: no paratypes Description Body (Fig. 1) elongated, shiny, reddish-brown, smooth, covered with long erected setae; length 3.2 mm. Head elongate, longer than wide, HL 0.60, HW 0.50, slightly narrower than pronotum and with short occipital carina in the middle. Frontal lobe transverse, with widely rounded anterior margin, lancet-like; eyes completely atrophied without indication of ocular carinae or thorns. Temples remarkably rounded and narrowed posteriorly, with long, erect setae. Frons with two depressions between antennal tubercles, vertexal foveae well defined, deep; maxillary palpi small, III blade shaped (0.25/0.08) as long as I-II together. Mandibles very strong. Antennae relatively short, distinctly shorter than body. All antennomeres elongate, scape 0.20 mm long / 0.11 mm wide, pedicel 0.17 mm long / 0.08 mm wide, length/width of antennomeres in mm (from III to XI): 0.015/0.057, 0.12/0.05, 0.14/0.05, 0.10/0.04, 0.13/0.04, 0.10/0.04, 0.15/0.08, 0.14/0.09, 0.30/0.10. Pronotum of the same length as head, PL 0.60 mm, PW 0.53 mm, barrel-shaped, almost in the middle slightly wider than head, median fovea shallow and elongate, lateral fovea well defined, deep. Elytra distinctly longer than wide, EL 1.0 mm, EW 0.80 mm. Abdomen almost as wide as elytra, first visible tergit transverse, (0.58 mm long / 0.82 mm wide). External stria diffuse with a tergal margin, internal stria very short, distance between them 0.25 mm, with basal shallow depression. Legs long and slender, mesofemura club shaped. The last abdominal tergit simple, without any fissure-like structures. Pygidium with triangular blunt apex. Etymology After Nyx (gr. Νύξ), in Greek mythology the goddess of the night, offspring of Chaos, and the mother of Aether and Hemera (Day) by Erebus (Darkness), which reside in the underworld in the depth of Tartarus. Biokovoamaurops, a new troglobitic genus of Amauropini (Coleoptera: Staphylinidae: Pselaphinae) from Biokovo Mt., Dalmatia Habitat and ecology Basic data Gradska špilja cave (Figs 2 and 3), at 746 m asl, depth -1.8 m, length 26.5 m, Map in Fig. 4. Microclimate Ta = 7.8-11.1 °C; Ts = 6.7-11.7 °C; RH: 99-100%, CO2 = 933-2100 ppm; based on measurements performed by the second author on several visits. Basic habitats Natura 2000: 8310; NKS H.1.1.4. Caves and cave systems with troglobitic invertebrates LT for taxa Neighbouring Samogorska špilja cave is LT for Thaumastocephalus roglici Pavićević, Ozimec, Besuchet & Cuccodoro, 2024. This recently described species occurred also in Gradska špilja cave (Pavićević et al. 2024b). Other taxa in LT Gastropoda: Semilimax sp., Spelaeoconcha sp.; Isopoda: Alpioniscus sp., Armadillidium sp., Oroniscus sp., Strouhaloniscus sp., Trichoniscus sp.; Chilopoda: Lithobius sp.; Diplopoda: Apfelbeckia sp., Brachydesmus sp., Dyocerasoma sp, Macrochaetosoma sp.; Acari: Rhagidia sp.; Symphyla: Scutigerella sp; Araneae: Stalagtia sp., Sulcia sp.; Opiliones: Cyphophthalmus sp., Nelima sp.; Palpigradi: Eukoenenia sp.; Pseudoscorpiones: Chthonius sp., Neobisium sp.; Scorpiones: Euscorpius sp., Collembola: Bilobella sp., Heteromurus sp., Orchesella sp., Tomocerus sp., Verhoeffiella sp.; Diplura: Plusiocampa (Stygiocampa) sp.; Zygentoma: Coletinia sp.; Coleoptera: Neotrechus sp., Speonesiotes sp., Neuraphes sp., Pygoxion sp., Tychobythinus sp., Thaumastocephalus roglici Pavićević, Ozimec, Besuchet & Cuccodoro, 2024; Diptera: Speolepta sp.; Orthoptera: Dolichopoda araneiformis Germar, 1838, Gryllomorpha sp., Troglophilus sp.; Lepidoptera: Triphosa sp. (after Pavićević et al. 2024b, supplemented) Remark Biokovoamaurops nyx gen. n., sp. n. is a species found in a small, relatively cold cave, air temperature 7.8-11 °C and substrate 6.7-11 °C, depending on the time of year, but with permanent air humidity 99-100%. For specimens found in small, real cave habitats, it is difficult to exactly define where they can occur, due to the proximity of deeper, inner, still unknown cave habitats, as well as interstitial cracks or channels. Fig. 1. Biokovoamaurops nyx gen. n., sp. n., habitus (by M. Popović). Distribution Known only from the type locality, Gradska špilja cave, located on the eastern part and N slopes on Biokovo Mountain (Figs 2-4). Biokovoamaurops nyx gen. n., sp. n. can be defined as an endemic species for the Natura 2000 site Biokovo (HR5000030), Nature Park Biokovo, Geopark BiokovoImotski lakes, Biokovo Mt., Split-Dalmatia County, Croatia, EU and Dinarides. Discussion This new Amauropini genus, Biokovoamaurops gen. n., shows a high level of similarity with the genus Seracamaurops, especially their smaller representatives such as S. popovici (Pavićević et al. 2008) or S. cadmei (Pavićević and Ozimec 2013) (Fig. 5) with respect to the following morphological characters: general body shape (habitus), length of antenna, disposition of the vertexal fovea as well as basal pronotal fovea, diffuse external stria with tergal margin, with short internal stria and long and slender legs with clubshaped mesofemora. It differs from Seracamaurops because of the presence of a distinctly wider head in the region of genae, broader pronotum, without the fissures of the last abdominal tergit. The biogeography of the three troglobitic Amauropini genera, such as Biokovoamaurops gen. n., Seracamaurops (subgenera Cordiamaurops and Seracamaurops) and Trogla- D. Pavićević et R. Ozimec maurops, is shown by the unique position of the genus Biokovoamaurops gen. n. in the Dinaric region (Fig. 6), according to the biogeography of the Dinaric cave fauna (Ozimec et al. 2009). While the other two genera are members of the South Dinaric biogeographic region, Biokovoamaurops gen. n is a member of the Central Dinaric, so-called Dalmatian, biogeographic region. With respect to the tectonics of the Dinarides, Seracamaurops and Biokovoamaurops gen. n. belong to the deeply karstified Dinaric tectonic zone, while Troglamaurops belongs to the Adriatic tectonic zone, which is strongly influenced by the Adriatic microplate. The genus Seracamaurops is distributed mainly in the mountainous part of eastern Herzegovina, in Bosnia and Herzegovina, and in the Mediterranean mountains of Montenegro, but also in Croatia, on Mount Sniježnica, part of the Konavle region (Fig. 6). The genus Troglamaurops is mainly distributed in the Southern Dalmatia (Dubrovnik-Neretva County) in Croatia, but also in eastern Herzegovina in Bosnia and Herzegovina, while the genus Biokovoamaurops gen. n. is currently known only in Croatia. Fig. 2. Entrance of Gradska špilja cave, view from the cave channel (photo by R. Ozimec). Fig. 3. Cave habitat of Gradska špilja cave, view from the entrance (photo by R. Ozimec). Biokovoamaurops, a new troglobitic genus of Amauropini (Coleoptera: Staphylinidae: Pselaphinae) from Biokovo Mt., Dalmatia Fig. 4. Map of Gradska špilja cave (by M. Pavlek, measured by H. Cvitanović, B. Jalžić and P. Rade). Fig. 5. Comparative drawings of Seracamaurops cadmei (A) and Biokovoamaurops nyx gen. n., sp. n. (B) (by M. Popović). D. Pavićević et R. Ozimec In close proximity to the Gradska špilja cave (Biokovoamaurops nyx gen. n., sp. n. type locality), two species of edaphic genus Paramaurops are present, both with atrophied eyes. Paramaurops alenkirini Hlaváč, Bregović & Jalžić, 2020 was described from the entrance area of the cave, Golubinka u Gaju, on Mihovil Mt. a part of Vrgorac Mountains, approximately 15 km straight-line distance from Gradska špilja cave. Another species, Paramaurops apfelbecki (Ganglbauer, 1896) is widely present in the region of middle Dalmatia, also on Matokit Mt. a part of Vrgorac mountain chain rather close to Gradska špilja cave. In the same wider area, Hlavač et al. (2020) found three more new, undescribed species of this genus. The genus Paramaurops with numerous taxa (62 after Hlavač et al. 2020) is present in the Mediterranean. The majority of the taxa are distributed in France and Italy and 10 species are found in the Balkan Peninsula (Hlavač et al. 2020). The distribution of the newly described genus, Biokovoamaurops gen. n. is currently completely unknown, but it can be predicted for caves at relatively higher altitudes, as well as cooler microclimates, in the Primorski mountain range, next to Biokovo (1762 m), including from the southeastern to the northwestern part of the Rilić massif (1155 m), Omiška Dinara (864 m), Mosor (1339 m) and Kozjak (779 m). But, perhaps also in the hilly mountainous area in the hinterland of Mount Biokovo, the so-called Vrgorac Mountains, including Matokit (1062 m), Mihovil (1247 m) and Šibenik (1314 m), as well as on some neighbouring mountains in Herzegovina. It should be emphasized that the genus Thaumastocephalus, which is most likely a syntropic genus with Biokovoamaurops gen. n., is also widespread on both of these mountain ranges. The type locality, Gradska špilja cave, as well as the neighbouring caves Matijaševa peć and Samogorska špilja (all three grouped above the village of Župa, on the northern slopes of Biokovo), were visited and investigated several times after 25-05-2004 (the date that the specimen of this new species was found), in order to find new specimens (2506-2004, 19-11-2005, 04-04-2006, 21-06-2007, 15-11-2010, 15-11-2011, 08-05-2012, 05-11-2015, and 23-06-2017). The most recent attempt to investigate these caves was conducted in the spring of 2024, when it was discovered that the path to the caves was heavily overgrown with vegetation and that it was impossible to reach the caves without prior cutting, cleaning, and clearly marking the path to the cave entrance. Unfortunately, even after many visits to the type locality, we have not been able to find any other specimens. Identification of a male specimen would be especially informative, because the study of its aedeagus could lead us to the correct position of this new genus and species among the Amauropini. We hope that future systematic research will lead us to the discovery of male individuals, and perhaps even further species of the newly described genus. Fig. 6. Simplified distribution map of three troglobitic Amauropini genera: Biokovoamaurops gen. n. (red line), Seracamaurops (black line) and Troglamaurops (blue line). Biokovoamaurops, a new troglobitic genus of Amauropini (Coleoptera: Staphylinidae: Pselaphinae) from Biokovo Mt., Dalmatia ACKNOWLEDGEMENTS The authors owe special gratitude to our colleagues and friends: to Predrag Rade, a speleologist from Karlovac, for his help and support during speleological and biospeleological research on Mount Biokovo; to Martina Pavlek for creating a topographic map of the type locality; to Branko Jalžić and Hrvoje Cvitanović for their assistance in speleological and biospeleological research of the cave; and to Momčilo Popović (Zemun, Serbia) for his excellent drawing of the habitus of the new species. REFERENCES Ganglbauer L. 1896. Nove Pselaphide iz Bosne i Hercegovine. Glasnik Zemaljskog Muzeja u Bosni i Hercegovini. 8/2:221–224. Hlaváč P, Bregović P & Jalžić B. 2020. Endogean and cavernicolous Coleop - tera of the Balkans. XXII. Two new species of Paramaurops Jeannel, 1948 (Coleoptera, Staphylinidae, Pselaphinae) from Croatia. Natura Croatica, 29/1:1–8. https://doi.org/10.20302/NC.2020.29.1 Hlaváč P, Ozimec R, Pavićević D. 2008. Catalogue of the troglobitic Pselaphinae (Coleoptera, Staphylinidae) of the Balkan peninsula, with a key to genera. In: Pavićević D, Perreau M, editors: Advances in the studies of the fauna of the Balkan Peninsula. Papers dedicated to the memory of Guido Nonveiller. Institute for Nature Conservation of Serbia, Belgrade, Monographs. 22:307–328. Hlaváč P, Perreau M, Čeplík D. 2017. The subterranean beetles of the Balkan Peninsula. Prague: Czech University of Life Sciences, Faculty of Forestry and Wood Sciences, Department of Forest Protection and Entomology. 267 p. Lohaj R, Pavićević D, Lakota J. 2023. Two new species of Seracamaurops Winkler (Coleoptera: Staphylinidae: Pselaphinae: Amauropini). Biologia Serbica. 45(1):35–47. Nonveiller G, Pavićević D. 2008. Une nouvelle espéce et deux nouveaux sous-genres de Seracamaurops, avec un Catalogue des Amauropini Méditerranées (Coleoptera: Staphylinidae: Pselaphidae). In: Pavićević D, Perreau M, editors: Advances in the studies of the fauna of the Balkan Peninsula. Papers dedicated to the memory of Guido Nonveiller. Institute for Nature Conservation of Serbia, Belgrade, Monographs. 22:249–268. Ozimec R, Bedek J, Gottstein S, Jalžić B, Slapnik R, Štamol V, Bilandžija H, Dražina T, Kletečki E, Komerički A, et al. 2009. Crvena knjiga špiljske faune Hrvatske (Red book of Croatian cave dwelling fauna). SINP, Zagreb. 371 p. Pavićević D, Hlaváč P, Lakota J. 2008. Four new species of Seracamaurops (Coleoptera, Staphylinidae, Pselaphinae) from the Southern Dinarids. In: Pavićević D, Perreau M, editors: Advances in the studies of the fauna of the Balkan Peninsula. Papers dedicated to the memory of Guido Nonveiller. Institute for Nature Conservation of Serbia, Belgrade, Monographs. 22:269–280. Pavićević D, Ozimec R. 2013. Seracamaurops (Seracamaurops) cadmei n. sp. (Coleoptera: Staphylinidae: Pselaphinae: Amauropini) from Mt. Sniježnica (Konavle): first representative of the genus in Croatia. Biologia Serbica. 35(1-2):62–67. Pavićević D, Ozimec R, Besuchet C, Cuccodoro G. 2024a: Two new species of the genus Troglamaurops Ganglbauer 1903 (Coleoptera, Staphylinidae, Pselaphinae, Amauropini) from Southern Dinarides. Fauna Balkana. 5:122–138. Pavićević D, Ozimec R, Besuchet C, Cuccodoro G. 2024b: Ten new spe - cies of the genus Thaumastocephalus Poggi et al. 2001 (Coleoptera: Staphylinidae: Pselaphinae) from Mount Biokovo and neighbouring mountains in Central Dinarides. Fauna Balkana. 5:89–121.