小柯机器人

中国科学院古脊椎动物与古人类研究所朱敏团队。相关论文发表在2022年9月28日出版的《自然》杂志上。

研究人员描述了来自中国下志留纪的软骨鱼类Fanjingshania renovata gen.et sp.nov.（新塑梵净山鱼）遗骸（皮板、鳞片和鳍刺），其年代早于最早的有颌脊椎动物的铰接化石。梵净山鱼拥有真皮肩腰板和鳍刺，与软骨鱼类的一个亚群中的鳍刺有着惊人的解剖学相似性。然而，在软骨鱼类中，它表现出类似于骨鱼类的鳞齿（皮齿）的再吸收性脱落，并且在其刺中没有牙源组织，这是独一无二的。这些研究结果表明，在软骨鱼类的干群中独立地获得了这些条件，使梵净山鱼加入了越来越多的分类群，嵌套在传统定义的棘齿动物中。梵净山鱼的发现为提议的早志留纪有颌脊椎动物在下泥盆纪系列化石记录中广泛出现之前的辐射提供了最有力的支持。

据了解，现代软骨鱼类（软骨鱼类）和骨鱼类（骨质鱼类和四足动物）的代表具有截然不同的骨骼解剖和发育轨迹，强调了这两个支系的遥远的演化分裂。最近对上志留纪和泥盆纪有颌脊椎动物的研究工作发现了类似的骨骼状况，模糊了骨鱼类、软骨鱼类及其有颌类祖先之间的传统区别。

附：英文原文

Title: Spiny chondrichthyan from the lower Silurian of South China

Author: Andreev, Plamen S., Sansom, Ivan J., Li, Qiang, Zhao, Wenjin, Wang, Jianhua, Wang, Chun-Chieh, Peng, Lijian, Jia, Liantao, Qiao, Tuo, Zhu, Min

Issue&Volume: 2022-09-28

Abstract: Modern representatives of chondrichthyans (cartilaginous fishes) and osteichthyans (bony fishes and tetrapods) have contrasting skeletal anatomies and developmental trajectories1,2,3,4 that underscore the distant evolutionary split5,6,7 of the two clades. Recent work on upper Silurian and Devonian jawed vertebrates7,8,9,10 has revealed similar skeletal conditions that blur the conventional distinctions between osteichthyans, chondrichthyans and their jawed gnathostome ancestors. Here we describe the remains (dermal plates, scales and fin spines) of a chondrichthyan, Fanjingshania renovata gen. et sp. nov., from the lower Silurian of China that pre-date the earliest articulated fossils of jawed vertebrates10,11,12. Fanjingshania possesses dermal shoulder girdle plates and a complement of fin spines that have a striking anatomical similarity to those recorded in a subset of stem chondrichthyans5,7,13 (climatiid ‘acanthodians’14). Uniquely among chondrichthyans, however, it demonstrates osteichthyan-like resorptive shedding of scale odontodes (dermal teeth) and an absence of odontogenic tissues in its spines. Our results identify independent acquisition of these conditions in the chondrichthyan stem group, adding Fanjingshania to an increasing number of taxa7,15 nested within conventionally defined acanthodians16. The discovery of Fanjingshania provides the strongest support yet for a proposed7 early Silurian radiation of jawed vertebrates before their widespread appearance5 in the fossil record in the Lower Devonian series.

DOI: 10.1038/s41586-022-05233-8

Source: https://www.nature.com/articles/s41586-022-05233-8

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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