三叠纪双足类显示爬行动物皮肤附属物的早期多样化，这一成果由斯图加特国家自然历史博物馆Rainer R. Schoch研究团队经过不懈努力而取得。2025年7月23日出版的《自然》发表了这项成果。

这里该课题组人员介绍了Mirasaura grauvogeli，一种来自中三叠纪的小型底辟动物（约247 数百万年前），由细长的被附属物沿着背部连续延伸而成，类似于人们知之甚少的三叠纪爬行动物Longisquama。尽管Mirasaura有着表面上类似鸟类的头骨，但它与两栖动物并没有密切的关系，而是完全属于三叠纪爬行动物分支Drepanosaaurmorpha。保存在其外皮附属物中的黑素体在几何形状上与羽毛中的黑素体一致，但与爬行动物皮肤或哺乳动物毛发中的黑素体不一致。

然而，Mirasaura的被膜附属物的形态和系统发育位置表明它们在结构上与活羊膜动物的羽毛或其他被膜附属物不相同。他们的研究结果表明，复杂的外皮附属物并不局限于无肢动物和羊膜动物中的哺乳动物，而是在所有现存爬行动物的基础谱系中进化而来的，这对他们对爬行动物外皮进化的理解提出了挑战。

据介绍，鸟类羽毛和哺乳动物毛发等复杂的外皮附属物在四足动物的进化过程中起着重要作用，在绝缘、感觉、展示和飞行等方面发挥着重要作用。虽然羽毛和毛发分别起源于鸟类和哺乳动物的茎系，但它们潜在的基因调控网络有着更深的羊膜根。然而，由于缺乏化石证据，对羊膜附属物的早期进化仍然知之甚少。

附：英文原文

Title: Triassic diapsid shows early diversification of skin appendages in reptiles

Author: Spiekman, Stephan N. F., Foth, Christian, Rossi, Valentina, Gasc Martn, Cristina, Slater, Tiffany S., Bath Enright, Orla G., Dollman, Kathleen N., Serafini, Giovanni, Seegis, Dieter, Grauvogel-Stamm, La, McNamara, Maria E., Sues, Hans-Dieter, Schoch, Rainer R.

Issue&Volume: 2025-07-23

Abstract: Complex integumentary appendages such as avian feathers and mammalian hair play a principal role in tetrapod evolution, with critical functions in insulation, sensation, display and flight. Although feathers and hair originated in the stem-lineages of birds and mammals, respectively1,2, their underlying gene regulatory network has much deeper amniote roots3. The early evolution of amniote integumentary appendages, however, remains poorly understood because of the absence of fossil evidence. Here we present Mirasaura grauvogeli, a small-sized diapsid from the Middle Triassic epoch (about 247million years ago) with a distinctive crest formed by elongate integumentary appendages extending serially along its back, similar to those of the poorly understood Triassic reptile Longisquama4,5,6,7. Despite its superficially bird-like skull, Mirasaura is not closely related to avemetatarsalians but instead belongs to the exclusively Triassic reptilian clade Drepanosauromorpha8. Melanosomes preserved in its integumentary appendages are consistent in geometry with melanosomes of feathers but not those of reptilian skin or mammalian hair. Nevertheless, the morphology of the integumentary appendages and phylogenetic placement of Mirasaura indicate that they are not structurally homologous to feathers or other integumentary appendages in living amniotes. Our findings show that complex integumentary appendages are not restricted to avemetatarsalians and mammaliaforms among amniotes and evolved in a lineage basal to all extant reptiles, challenging our understanding of the evolution of the reptilian integument.

DOI: 10.1038/s41586-025-09167-9

Source: https://www.nature.com/articles/s41586-025-09167-9