A New Giant Salamander (Urodela, Pancryptobrancha) from the Miocene of Eastern Europe (Grytsiv, Ukraine)
A New Giant Salamander (Urodela, Pancryptobrancha) from the Miocene of Eastern Europe (Grytsiv, Ukraine)
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DOI：
10.1080/02724634.2013.722151
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
D. Vasilyan;M. Böhme;V. M. Chkhikvadze;Y. Semenov;W. Joyce
中科院分区：
文献类型：
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作者：
D. Vasilyan;M. Böhme;V. M. Chkhikvadze;Y. Semenov;W. Joyce
摘要我们提出了新的和保存完好的大蝾螈材料从中新世的Grytsiv地点，乌克兰。本文描述了一个新分类群：高颌乌尾鱼Ukrainurus hypsognathus，gen. et sp. nov.。下颌畸形的特征在于骨化不良的骨组织、相对不灵活的下颌骨、高的齿骨、在齿骨的舌面上的嵴、由齿板和齿下表面组成的齿骨的齿部、在鳞骨上存在背隆起、在枕骨上存在宽的髁周小面、极度伸长的前关节突和具有伸长的椭圆形基部的血管突。此外，U.高颌龙显示出强壮的下颌提肌，表明有很大的咬合力。对所有已知的第三纪和现代巨型蝾螈的系统发育分析恢复了亚洲和北美隐鳃类的单系群，但将U。高颌外冠组隐鳃科。这一结果表明，隐鳃科起源于亚洲，并分散到北美。冠隐鳃科最古老的代表是来自蒙古Nemegt盆地古新世末期的Aviturus exsecratus。
ABSTRACT We present new and well-preserved giant salamander material from the Miocene of the Grytsiv locality, Ukraine. Disarticulated skull and postcranial bones from two individuals are described as a new taxon, Ukrainurus hypsognathus, gen. et sp. nov. U. hypsognathus is characterized by poorly ossified bone tissues, relatively inflexible mandibles, a high dentary, a crista on the lingual surface of the dentary, a pars dentalis of the dentary that is composed of a dental lamina and a subdental surface, presence of an eminentia dorsalis on the squamosal, a broad pericondylar facet on the occipital, extremely elongated prezygapophyses, and hemal processes with an elongate, oval base. Moreover, U. hypsognathus shows evidence of strong mandibular levator muscles that indicate great biting force. A phylogenetic analysis of all well-understood Tertiary and Recent giant salamanders recovers a monophyletic group of Asian and North American cryptobranchids, but places U. hypsognathus outside crown group Cryptobranchidae. This result suggests that Cryptobranchidae originated in Asia and dispersed to North America. The oldest representative of crown Cryptobranchidae is Aviturus exsecratus from the terminal Paleocene of the Nemegt Basin, Mongolia.