TAXONOMIC REVISON OF THE BASAL NEORNITHISCHIAN TAXA THESCELOSAURUS AND BUGENASAURA
TAXONOMIC REVISON OF THE BASAL NEORNITHISCHIAN TAXA THESCELOSAURUS AND BUGENASAURA
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DOI：
10.1671/039.029.0328
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发表时间：
2009-09-12
影响因子：
1.4
通讯作者：
Clarke, Julia A.
中科院分区：
文献类型：
--
作者：
Boyd, Clint A.;Brown, Caleb Marshall;Clarke, Julia A.
关于北美Maastrichtian基底新鸟臀目分类群的分类和系统发育关系存在相当大的争议。在疏忽塞塞隆龙（Thescelosaurus neglectus，USNM 7758）的副模式标本中发现了先前未被识别的颅骨材料，沿着，并对两个保存了几乎完整的头骨和下颌骨的新标本进行了检查，这使得人们可以重新评估先前被认为是塞隆龙的标本，这些标本保存了颅骨材料，包括Bugenasaura infernalis（SDSM 7210）和Parksosaurus warreni（ROM 804）的正模标本。进行了系统发育分析，包括作为终端的B的全型。infernalis和P. warreni，T.疏忽，和六个标本以前提到Thescelosaurus。这项分析是第一次恢复一个分支，包含所有的基础新鸟臀目分类群从白垩纪的北美。其中P. warreni被发现为Thescelosaurus分支的姐妹分类群，该分支的单系性由五个颅的自形性支持。分析结果支持：（1）Bugenasaura与Thescelosaurus的同步化;（2）从Thescelosaurus中移除ROM 804;（3）Thescelosaurus garbanii的有效性及其对Thescelosaurus的引用，尽管它的碎片性质。目前，帕克索龙和塞隆龙是唯一在北美洲马斯特里赫特时代沉积物中明确已知的新鸟臀目基底类群。而其他基础新鸟臀目分类群提出了证明fossorial行为（即，Orodromeus、Oryctodromeus和Zephyrosaurus）在坎帕尼亚期和更古老的沉积物中被发现。这种时间隔离可能支持以前的假设，在最后的白垩纪在北美的环境或生态转变。
Considerable controversy surrounds the taxonomy and phylogenetic relationships of Maastrichtian basal neornithischian taxa from North America. Discovery of previously unrecognized cranial material from the paratype specimen of Thescelosaurus neglectus (USNM 7758), along with the examination of two new specimens that preserve nearly complete skulls and mandibles, allows for reevaluation of specimens previously referred to Thescelosaurus that preserve cranial material, including the holotypes of Bugenasaura infernalis (SDSM 7210) and Parksosaurus warreni (ROM 804). A phylogenetic analysis was conducted that included as terminals the holotypes of B. infernalis and P. warreni, the type series of T. neglectus, and six specimens previously referred to Thescelosaurus. This analysis is the first to recover a clade containing all basal neornithischian taxa from the Cretaceous of North America. within which P. warreni is recovered as the sister taxon to a Thescelosaurus clade whose monophyly is supported by five cranial autapomorphies. The results of this analysis Support: (1) the synonymization of Bugenasaura with Thescelosaurus: (2) the removal of ROM 804 from Thescelosaurus: and (3) the validity of Thescelosaurus garbanii and its referral to Thescelosaurus despite its fragmentary nature. Currently, Parksosaurus and Thescelosaurus are the only basal neornithischian taxa definitively known from Maastrichtian age sediments of North America. while other basal neornithischian taxa proposed to demonstrate fossorial behavior (i.e.. Orodromeus, Oryctodromeus, and Zephyrosaurus) are known from Campanian and older sediments. This temporal segregation may support previous hypotheses of an environmental or ecological shift during the latest Cretaceous in North America.