Institut für Biologie, Humboldt Universität zu Berlin, Berlin, Germany.
Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany.
PeerJ. 2023 Jul 7;11:e15378. doi: 10.7717/peerj.15378. eCollection 2023.
Gorgonopsians are among the most recognizable groups of synapsids from the Permian period and have an extensive but mostly cranial fossil record. By contrast, relatively little is known about their postcranial anatomy. Here, we describe a nearly complete, semi-articulated skeleton of a gorgonopsian (identified as ) from the late Permian Assemblage Zone of the South African Karoo Basin and discuss its paleobiological implications. Known gorgonopsian postcrania indicate morphological conservatism in the group, but the skeletal anatomy of does differ from that of other gorgonopsians in some respects, such as in the triangular radiale and short terminal phalanges in the manus, and a weakly developed distinction between pubis and ischium in ventral aspect of the pelvic girdle. Similarities between the specimen described herein and a historically problematic specimen originally referred to " cf. " confirm referral of the latter specimen to . Since descriptions of gorgonopsian postcrania are rare, new interpretations of the lifestyle and ecology of Gorgonopsia can be drawn from our contribution. We conclude that gorgonopsians were likely ambush predators, able to chase their prey over short distances and pin them down with strong forelimbs before using their canines for the kill. This is evidenced by their different fore- and hindlimb morphology; the former stouter and more robust in comparison to the longer, more gracile, back legs. Furthermore, the completeness of the study specimen facilitates calculation of an estimated body mass of approximately 98 kg, similar to that of a modern lioness.
犬齿兽是二叠纪时期最具代表性的合弓动物之一，拥有广泛但主要是颅骨化石记录。相比之下，人们对它们的后躯解剖结构知之甚少。在这里，我们描述了来自南非卡鲁盆地晚二叠世组合带的一种近乎完整的、半关节的犬齿兽骨架（鉴定为 ），并讨论了其古生物学意义。已知的犬齿兽后躯表明该类群在形态上具有保守性，但 的骨骼解剖结构在某些方面与其他犬齿兽不同，例如，手部的三角形桡骨和短末节指骨，以及骨盆带腹侧耻骨和坐骨之间发育较弱的区别。本文描述的标本与一个历史上有问题的标本（最初被归为“ cf. ”）之间的相似性证实了后者被归为 。由于对犬齿兽后躯的描述很少，因此可以从我们的研究中对犬齿兽的生活方式和生态学进行新的解释。我们得出结论，犬齿兽可能是伏击捕食者，能够在短距离内追逐猎物，并利用强壮的前肢将其固定在原地，然后用犬齿进行捕杀。这一点可以从它们不同的前肢和后肢形态得到证明；前者与较长、更优雅的后腿相比，更粗壮和强壮。此外，研究标本的完整性便于计算出一个大约 98 公斤的估计体重，类似于现代母狮的体重。
