New Material of the Choristodere Lazarussuchus (Diapsida, Choristodera) from the Paleocene of France
New Material of the Choristodere Lazarussuchus (Diapsida, Choristodera) from the Paleocene of France
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DOI：
10.1080/02724634.2012.716274
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
R. Matsumoto;E. Buffetaut;François Escuillié;S. Hervet;S. Evans
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文献类型：
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作者：
R. Matsumoto;E. Buffetaut;François Escuillié;S. Hervet;S. Evans
蛭形目是淡水水生爬行动物的一个分支，其分布严格属于月桂纲，其时间记录至少从中侏罗世延伸至中新世。大型的白垩纪-始新世新石器时代的chamsosaurus和Simoedosaurus是最熟悉的分类群，但许多较小的代表已经被认识。新石器化石在始新世从化石记录中消失了，但石器化石却以体型小、表面像蜥蜴的拉扎鲁苏龙的形式存活到了欧洲新第三纪。这个分类群最初是在法国晚渐新世被描述的，但后来在捷克共和国早中新世和德国晚渐新世被记录下来。尽管它的年代久远，但大多数系统发育分析都将Lazarussuchus置于或接近于编年史目树的底部，这意味着它有一段很长的未被记录的历史。在法国Menat的古新世晚期发现的Lazarussuchus标本部分填补了这一空白。因此，该属在西欧的水道中至少存在了30万年，而且可能比目前的记录显示的要广泛得多。一项新的系统发育分析证实了它的位置在新石器类群之外，但与非新石器类群的关系仍未完全解决。
ABSTRACT Choristodera is a clade of freshwater aquatic reptiles with a strictly Laurasian distribution and a temporal record extending from at least Middle Jurassic to Miocene. The large Cretaceous-Eocene neochoristoderes Champsosaurus and Simoedosaurus are the most familiar taxa, but many smaller representatives have since been recognized. Neochoristoderes disappeared from the fossil record in the Eocene, but choristoderes survived into the European Neogene in the form of the small, superficially lizard-like Lazarussuchus. This taxon was originally described from the late Oligocene of France but has subsequently been recorded from the early Miocene of the Czech Republic and the late Oligocene of Germany. Despite its age, most phylogenetic analyses place Lazarussuchus at or close to the base of the choristoderan tree, implying a very long unrecorded history. A new specimen of Lazarussuchus from the late Paleocene locality of Menat, France, partly fills that hiatus. The genus was thus present in the waterways of western Europe for at least 30 Ma, and was probably considerably more widespread than current records suggest. A new phylogenetic analysis confirms its placement outside Neochoristodera, but the relationships of non-neochoristoderan taxa remain incompletely resolved.