Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan.
Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan.
复制标题
作者：
Vasilyan D;Zazhigin VS;Böhme M
西西伯利亚目前的两栖和爬行动物群是古北界中多样性最小的，这是由于该地区占主导地位的不利气候条件的结果。人们对这些两栖动物群的起源和出现知之甚少。除了欧洲新近纪发现两栖和爬行动物化石遗骸较好的地区外，西亚的新近纪两栖爬行动物还没有得到充分的研究。为数不多的现有数据需要批判性的审查和新的解释，考虑到欧洲爬行动物的较新记录。将这一先前的数据与欧洲化石记录的数据进行比较，将提供该地区的古生物地理关系以及西西伯利亚现今动物群的起源和出现的数据。仍然需要对某些两栖动物谱系的最早出现情况进行概述。此外，解决这些知识差距的研究对分子生物学家校准分子时钟也是有用的。在这项研究中，我们仔细回顾了来自西西伯利亚、俄罗斯和哈萨克斯坦东北部40多个地区的两栖和爬行动物动物群的现有数据，这些地区从中新世中期到更新世早期。在这里，我们提供了新的解释，产生于我们对之前发表的和新的数据的评估。共鉴定出50多个两栖和爬行动物分类群，分别隶属于小水母科、隐鳍科、火蜥科、古背鱼科、熊鱼科、角叉鱼科、水虎科、蟾科、蛙科、壁虎科、蜥蜴科和斑潜蝇科。对这些群进行了古生物地理分析，并利用两栖动物组合的生物气候分析，估计了12个地点的古沉淀值。西西伯利亚新近纪组合以欧洲亲缘类群为主，如古北界、Bombina、Hyla、Bufo Bufo等，其中一小部分包括东古北界类群(如Salamandrella、Tylototriton、Bufotes viridis)。对于几个分类群(如Mioprous、Hyla、Bombina、Rana Temporaria)，西西伯利亚的出现代表了它们最东边的欧亚记录。最多样化的化石遗骸收藏是在中新世中期发现的。早更新世生物多样性较少，可能是由于北半球气候逐渐变冷所致。我们的研究结果显示，西西伯利亚早中新世至上新世降水发展的变化幅度比先前假设的要大。
The 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. In 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. The 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.