Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan

Abstract

BackgroundThe present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks.Methods and ResultsIn this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages.ConclusionThe Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae, Bombina, Hyla, Bufo bufo, and a small part of this assemblage included Eastern Palaearctic taxa (e.g. Salamandrella, Tylototriton, Bufotes viridis). For several taxa (e.g. Mioproteus, Hyla, Bombina, Rana temporaria), the Western Siberian occurrences represented their most eastern Eurasian records. The most diverse collection of fossil remains was found in the Middle Miocene. Less diversity has been registered towards the Early Pleistocene, potentially due to the progressive cooling of the climate in the Northern Hemisphere. The results of our study showed higher-amplitude changes of precipitation development in Western Siberia from the Early Miocene to the Pliocene, than previously assumed.

Fish, amphibian and reptilian faunas from latest Oligocene to middle Miocene localities from Central Turkey

“…In Claessens (1996Claessens ( , 1997, it has been referred to the genus Bufotes, but after critical revision, we refer it to Bufonidae indet. Whether Bufotes has entered from Asia to Europe via Turkey as suggested earlier (Claessens 1997;Vasilyan et al 2017), we cannot state with absolute confidence here. Further finds from early Miocene localities could shed more light on this palaeobiogeographic question.…”

“…Recently, Vasilyan et al (2017) analysed the European and western Asian amphibian and reptilian Neogene record, suggesting that Anatolia played an important role in the dispersal of some amphibians and reptilian lineages, especially during the early Miocene. Also Claessens (1997) suggested Anatolia t o b e a m i g r a t i o n r o u t e f o r t h e g e n u s B u f o t e s (=Pseudepidalea) for the migrations from Asia to Europe.…”

Northern Asian Pliocene–Pleistocene beremendiin shrews (Mammalia, Lipotyphla, Soricidae): a description of material from Russia (Siberia), Kazakhstan, and Mongolia and the paleobiology of Beremendia

“…1, 2; S1): Andreevka 1 (ANR/1B, ANR/1C), Andreevka 2 (ANR/2B), Kamen’-na-Obi (KMN), Kartashovo (KRT), Kizikha (KZH), Livenka (LVK), Razdol'e (RZD), Sibiryachikha (SBH), Speranskoye (SPR), Borehole #103/19 (BH-103/19), Beregovaya (BRG), Bural-Obo (BRB/C), Orkhon 1 (ORH/1A, ORH/1B), Shamar (SHM/A), Biteke 1 (BTK/1B, BTK/1C), and Lebyazhye (LBZ/C). All of these localities were mentioned by Zazhigin and Lopatin (2000, 2001), Zazhigin et al (2002), and Vasilyan et al (2017). The lithological and biostratigraphic descriptions of the localities have been published in several articles since the 1960s, including Vangeigeim et al (1966), Devjatkin and Zazhigin (1974), Zazhigin (1980, 1989), Devjatkin et al (1982), Zazhigin and Zykin (1984), Derevyanko and Maloletko (1992), Zykin et al (1987, 2007), and Zykin (2012).…”

The middle Miocene duck Chenoanas (Aves, Anatidae): new species, phylogeny and geographical range

“…Other components of the middle Miocene herpetofauna were similarly widespread in Europe and Asia (Vasilyan et al . , ). However, the age of Sansan (and hence biozone MN 6, for which it is a reference locality) is still debated.…”