Teleosauroidea is a clade of ancient crocodylomorphs that were integral components of coastal marine environments throughout the Jurassic. For nearly two centuries, one of the most familiar genera of teleosauroids has been Steneosaurus, encompassing nearly every teleosauroid species at some point. However, no type species has been designated for Steneosaurus under ICZN Code rules; the type specimen of the presumed type species S. rostromajorGeoffroy Saint-Hilaire, 1825 (MNHN.RJN 134c-d) is a chimera that has been largely neglected in the literature. Moreover, there is confusion as to which teleosauroid species it pertains to, and the genus Steneosaurus is often recovered as paraphyletic or polyphyletic in phylogenetic analyses. As such, the validity of Steneosaurus is uncertain. Here we formally designate S. rostromajor as the type species of Steneosaurus, designate a lectotype and re-evaluate MNHN.RJN 134c-d. We compare it with several well-known teleosauroids, including Lemmysuchus and ‘S.’ edwardsi. Due to lack of autapomorphic characters, poor preservation and a tortured taxonomic history, we find MNHN.RJN 134c-d to be an undiagnostic and unreliable specimen. Thus, we consider S. rostromajor as a nomen dubium and propose that the genus Steneosaurus is undiagnostic. This has profound implications for teleosauroid phylogenetics, which we will clarify in an upcoming paper.

中文翻译：

---

清空废纸bas：侏罗纪鳄纲剑龙的历史和分类学修订

Teleosauroidea是古代鳄形生物的进化枝，它们是整个侏罗纪沿海海洋环境的组成部分。近两个世纪以来，剑龙属是最熟悉的硬骨龙属之一，在某个时候几乎涵盖了所有硬骨龙的种类。但是，根据《 ICZN规则》，没有将任何种类的种类指定为剑龙。假定类型物种S的类型标本。rostromajor Geoffroy Saint-Hilaire，1825年（MNHN.RJN 134c-d）是一种在很大程度上被文献忽略的嵌合体。此外，存在分不清哪些teleosauroid它涉及到种，属狭蜥鳄属在系统发育分析中通常以副系统或多系统的形式回收。因此，剑龙的有效性尚不确定。在这里，我们正式指定小号。rostromajor作为类型物种狭蜥鳄属，指定一个选型和重新评估MNHN.RJN齿134c-d。我们将其与几种著名的硬骨龙进行比较，包括Lemmysuchus和“ S”。爱德华兹。由于缺乏拟态特征，保存不佳以及生物分类历史受折磨，我们发现MNHN.RJN 134c-d是无法诊断且不可靠的标本。因此，我们认为小号。rostromajor作为学校名称柱木并提出剑龙属是无法诊断的。这对硬骨膜系统发育有深远的影响，我们将在即将发表的论文中阐明这一点。