Revision of the early crocodylomorph Trialestes romeri (Archosauria, Suchia) from the lower Upper Triassic Ischigualasto Formation of Argentina: one of the oldest‐known crocodylomorphs
Revision of the early crocodylomorph Trialestes romeri (Archosauria, Suchia) from the lower Upper Triassic Ischigualasto Formation of Argentina: one of the oldest‐known crocodylomorphs
复制标题
来自阿根廷上三叠统下部伊斯奇瓜拉斯托组的早期鳄鱼形 Trialestes romeri（Archosauria，Suchia）的修订版：已知最古老的鳄鱼形之一
DOI：
10.1002/spp2.1056
复制
发表时间：
2016
影响因子：
2.3
通讯作者：
R. Irmis
中科院分区：
文献类型：
--
作者：
Agustina Lecuona;M. Ezcurra;R. Irmis
罗梅氏鳄（Trialestes romeri，Reig）是一种早期鳄形类，来自Icargualasto组（Icargualasto- Villa Unión Basin，阿根廷），也是该分支中最古老的成员之一。该物种的两个标本是已知的，正模标本（PVL 2561）和一个参考标本（PVL 3889），两者都由相关的颅和颅后遗骸组成。这些标本是不完整的，保存不好，从而导致以前的作者提出了不同的系统发育假说的物种。Trialestes romeri最初被解释为一种基底恐龙，后来被认为是一种具有一些马丘比丘特征（例如中跗踝关节，功能上的三趾足）的鳄形动物，甚至被认为是代表两个不同属的嵌合体。最近的一些工作者提到并讨论了Trialestes，但没有人详细描述它或将其纳入定量系统发育分析。在这里，我们详细描述了所有的材料分配到该物种和测试其系统发育关系使用一个全面的数据矩阵集中在早期的祖龙。我们支持将PVL 3889转介给Trialestes，并拒绝该标本中存在跗系踝关节。我们在鳄形目中发现了Trialestes，与鳄形目的关系比伪hesperosuchus，Hesperosuchus，Dromicosuchus和Sphenosuchus更近。世界各地的几个地层单位与Icargualasto地层大致同时代，也发现了早期的鳄鱼化石，如上圣玛利亚（巴西），北京（美国）和下马莱里（印度）地层。然而，从这些单位回收的鳄鱼标本更不完整，具有不确定的系统发育亲和力，或者是嵌合体的一部分。因此，Trialestes代表了迄今为止已知的最早的非鳄鱼形鳄鱼形分类群中最完整的已知。
Trialestes romeri (Reig) is an early crocodylomorph from the Ischigualasto Formation (late Carnian – early Norian; Ischigualasto – Villa Unión Basin, Argentina) and one of the oldest‐known members of this clade. Two specimens of this species are known, the holotype (PVL 2561) and a referred specimen (PVL 3889), both consisting of associated cranial and postcranial remains. These specimens are incomplete and poorly preserved thus leading previous authors to propose different phylogenetic hypotheses for the species. Trialestes romeri was originally interpreted as a basal dinosaur, subsequently considered to be a crocodylomorph with some dinosaurian characters (e.g. mesotarsal ankle joint, functionally tridactyl pes), and even proposed as a chimera representing two different genera. Some recent workers have mentioned and discussed Trialestes, but none have described it in detail or included it in a quantitative phylogenetic analysis. Here, we describe in detail all the material assignable to the species and test its phylogenetic relationships using a comprehensive data matrix focused on early archosaurs. We support the referral of PVL 3889 to Trialestes and reject the presence of a mesotarsal ankle joint in this specimen. We recovered Trialestes within Crocodylomorpha, closer to Crocodyliformes than Pseudhesperosuchus, Hesperosuchus, Dromicosuchus and Sphenosuchus. Several stratigraphical units worldwide approximately coeval with the Ischigualasto Formation, have also yielded early crocodylomorph remains, such as the upper Santa María (Brazil), Pekin (USA), and lower Maleri (India) formations. However, the crocodylomorph specimens recovered from those units are more incomplete, possess uncertain phylogenetic affinities, or are part of chimaerae. Therefore, Trialestes represents the most completely known of the earliest non‐crocodyliform crocodylomorph taxa known to date.
影响因子：
3.7
作者：
Ezcurra MD;Scheyer TM;Butler RJ
通讯作者：
Butler RJ
影响因子：
3.4
作者：
Butler RJ;Sullivan C;Ezcurra MD;Liu J;Lecuona A;Sookias RB
通讯作者：
Sookias RB