期刊
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
卷 136, 期 1, 页码 7-23出版社
OXFORD UNIV PRESS
DOI: 10.1046/j.1096-3642.2002.00023.x
关键词
Suchia Crocodylomorpha; morphology; phylogeny; character evolution
类别
New data on the braincase of the aetosaurian archosaur Stagonolepis robertsoni Agassiz are presented, based on new preparation, synthetic casting, and interpretation of fossil material from the Triassic Elgin Sandstones, Scotland. The metotic fissure is not divided by bone. The perilymphatic foramen is completely bound by bone, and faces away from the otic capsule in a posterolateral direction. A prominent subvertical ridge on the anterolateral edge of the exoccipital and upper part of the basioccipital cannot be directly associated with the subcapsular process of the chondrocranium of extant crocodilians. This ridge projects laterally beyond the ventral ramus of the opisthotic, and lies anterior to the external foramina for the hypoglossal nerve. The overall structure of the braincases (especially the otic region) of S. robertsoni and other aetosaurians, where known, is more similar (in terms of derived archosaurian characters) to those of crocodylomorphs than are the braineases of other major suchian groups. This provides evidence for the currently unorthodox hypothesis that, among major suchian clades, Aetosauria and Crocodylomorpha are each others' closest relatives. Support for this hypothesis is found in features of the palatine and prefrontal that have not been considered in recent studies of suchian phylogeny. This alternative phylogenetic hypothesis demands further investigation but, combined with the new morphological data that it explains, it provides a framework for the understanding of the evolution of the derived and distinctive braincase structure of extant crocodilians. (C) 2002 The Linnean Society of London.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据