A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton
A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton
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DOI：
10.1038/18665
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发表时间：
1999-03
期刊：
影响因子：
64.8
通讯作者：
Ji Qiang;Luo Zhexi;Shu-an Ji
中科院分区：
文献类型：
--
作者：
Ji Qiang;Luo Zhexi;Shu-an Ji
本文描述了中国辽宁晚侏罗世/早白垩世一种新的三齿类哺乳动物。这种新的哺乳动物是迄今为止已知的保存最完好的三齿兽骨骼的代表，三齿兽是最早的中生代哺乳动物群体之一，具有高度的多样性。这个新的三齿龙的颅后骨骼显示了一个镶嵌的特征，包括一个原始的骨盆带和后肢，但一个非常衍生的胸带，与衍生兽亚目的胸带非常相似。由于这个分类单元在哺乳动物的进化史中处于基础位置，其衍生的胸带表明，在中生代哺乳动物的进化中，同源性（由不相关谱系之间的独立进化产生的相似性）在颅后骨骼中与头骨和齿系中一样普遍。新的三齿龙的四肢结构表明它可能是一种地面生活的动物。
Here we describe a new triconodont mammal from the Late Jurassic/Early Cretaceous period of Liaoning, China. This new mammal is represented by the best-preserved skeleton known so far for triconodonts which form one of the earliest Mesozoic mammalian groups with high diversity. The postcranial skeleton of this new triconodont shows a mosaic of characters, including a primitive pelvic girdle and hindlimb but a very derived pectoral girdle that is closely comparable to those of derived therians. Given the basal position of this taxon in mammalian phylogeny, its derived pectoral girdle indicates that homoplasies (similarities resulting from independent evolution among unrelated lineages) are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals. Limb structures of the new triconodont indicate that it was probably a ground-dwelling animal.