New Craniodental Materials of Litolophus gobiensis (Perissodactyla, "Eomoropidae") from Inner Mongolia, China, and Phylogenetic Analyses of Eocene Chalicotheres
New Craniodental Materials of Litolophus gobiensis (Perissodactyla, "Eomoropidae") from Inner Mongolia, China, and Phylogenetic Analyses of Eocene Chalicotheres
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DOI：
10.1206/678.1
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发表时间：
2010-06-25
影响因子：
1.5
通讯作者：
Meng, Jin
中科院分区：
文献类型：
--
作者：
Bai, Bin;Wang, Yuanqing;Meng, Jin
本文描述了最近从该属的模式地区发现的新的头骨标本，并根据包含21个分类单元和58个头骨特征的数据矩阵对始新世合眼动物进行了系统发育分析。尽管在严格的成分共识树中没有很好地解决始新世脉石动物的系统发育关系，但50%的多数规则共识表明，存在两个最早的始新世后脉石化石谱系。第一个谱系代表了合点石器进化的主线，包括“Grangeria”Eomoropus和后始新世合点石器。第二个世系由Litolopus gobiensis和Grangeria canina组成，是主要世系的姐妹群和主干成员。派生的严格约简共识树，通过剪枝三个不稳定的类群，支持50%多数共识的一些树拓扑。在系统发育分析的基础上，对一些合点藻类的分类进行了修正，如“Grangeria”anarsius可能更好地被认为是最初所确定的Eomoropus属，E.ularorum是E.amarorum的姊妹分类单元，以及Lophiodon被排除在钩足纲之外，但与龟形目联系在一起。
We describe new craniodental specimens of Litolophus gobiensis recently unearthed from the type locality of the genus, and conduct phylogenetic analyses of Eocene chalicotheres based on a data matrix containing 21 taxa and 58 craniodental characters. Although the phylogenetic relationships of the Eocene chalicotheres arc not well resolved in the strict component consensus tree, the 50% majority rule consensus shows that two post earliest Eocene chalicothere lineages are present. The first lineage represents the main line of chalicothere evolution, including "Grangeria" Eomoropus, and post-Eocene chalicotheres. The second lineage, consisting of Litolophus gobiensis and Grangeria canina, is the sister group and stem member to the main lineage. The derivative strict reduced consensus tree, with three unstable taxa pruned, supports some tree topologies of the 50% majority consensus. The taxonomy of some chalicothere taxa is revised based on the phylogenetic analyses, such as "Grangeria" anarsius being probably better referred to the genus Eomoropus as originally identified, E. ulterior being the sister taxon to E. amarorum, and Lophiodon being excluded from the Ancylopoda but allied with the Ceratomorpha.