小柯机器人

智利大学Sergio Soto-Acuña和Alexander O. Vargas团队的研究发现智利亚南极地区甲龙进化过程中出现了奇特的尾巴武器。2021年12月1日出版的《自然》杂志在线发表了这项成果。

研究人员描述了智利最南端麦哲伦晚期白垩纪晚期小型（约 2 米）装甲恐龙几乎完整的半铰接骨架，该地区在生物地理上与南极洲西部有关。 Stegouros elengassen进化出了一种不同于任何恐龙的大尾巴武器：具有扁平的叶状结构，由七对侧向突出的骨皮形成，包裹着远离尾巴的部分。Stegouros具有甲龙类的颅骨特征，但主要与其祖先后颅骨骨骼相似，具有一些类似剑龙的特征。

系统发育分析认为剑龙属于甲龙目；具体来说，它与来自澳大利亚的昆巴拉龙和来自南极洲的Antarctopelta 有关，这共同形成了一个冈瓦纳甲龙分支并被认为是最早从所有其他甲龙中分离出来的一个分支。Antarctopelta的大骨皮和特殊的尾椎骨表明它具有类似于Stegouros的尾部武器。该研究提出了一个新的进化枝，即副龙目，包括剑龙的祖先-但不包括甲龙-以及由该祖先进化而来的所有后代。

据了解，装甲恐龙以其进化出特殊的尾巴武器而闻名-如剑龙的成对尾刺和高等甲龙的重尾棒。冈瓦纳大陆南部的装甲恐龙罕见且神秘，其可能包括甲龙科最早的分支。

附：英文原文

Title: Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile

Author: Soto-Acua, Sergio, Vargas, Alexander O., Kaluza, Jonatan, Leppe, Marcelo A., Botelho, Joao F., Palma-Liberona, Jos, Simon-Gutstein, Carolina, Fernndez, Roy A., Ortiz, Hctor, Milla, Vernica, Aravena, Brbara, Manrquez, Leslie M. E., Alarcn-Muoz, Jhonatan, Pino, Juan Pablo, Trevisan, Cristine, Mansilla, Hctor, Hinojosa, Luis Felipe, Muoz-Walther, Vicente, Rubilar-Rogers, David

Issue&Volume: 2021-12-01

Abstract: Armoured dinosaurs are well known for their evolution of specialized tail weapons—paired tail spikes in stegosaurs and heavy tail clubs in advanced ankylosaurs1. Armoured dinosaurs from southern Gondwana are rare and enigmatic, but probably include the earliest branches of Ankylosauria2,3,4. Here we describe a mostly complete, semi-articulated skeleton of a small (approximately 2m) armoured dinosaur from the late Cretaceous period of Magallanes in southernmost Chile, a region that is biogeographically related to West Antarctica5. Stegouros elengassen gen. et sp. nov. evolved a large tail weapon unlike any dinosaur: a flat, frond-like structure formed by seven pairs of laterally projecting osteoderms encasing the distal half of the tail. Stegouros shows ankylosaurian cranial characters, but a largely ancestral postcranial skeleton, with some stegosaur-like characters. Phylogenetic analyses placed Stegouros in Ankylosauria; specifically, it is related to Kunbarrasaurus from Australia6 and Antarctopelta from Antarctica7, forming a clade of Gondwanan ankylosaurs that split earliest from all other ankylosaurs. The large osteoderms and specialized tail vertebrae in Antarctopelta suggest that it had a tail weapon similar to Stegouros. We propose a new clade, the Parankylosauria, to include the first ancestor of Stegouros—but not Ankylosaurus—and all descendants of that ancestor.

DOI: 10.1038/s41586-021-04147-1

Source: https://www.nature.com/articles/s41586-021-04147-1

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
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