中国科学院古脊椎动物与古人类研究所朱敏团队发现最古老的有颌类牙齿。2022年9月28日出版的《自然》杂志发表了这项成果。
研究人员提供了目前最早的有颌脊椎动物的直接证据，并首次报道了双列黔齿鱼（Qianodus duplicis），这是一个早志留纪有颌类的新属和种，这是根据从中国贵州分离到的齿旋。这些齿旋拥有不脱落的牙齿，并排列成一对行，展示了在现代有颌类群体中发现的一些特征。这些特征包括在舌部增加牙齿，并在整个齿旋发育过程中保持这种模式。这些数据将有齿有颌类的记录延长了1400万年，从晚志留世到早志留世（大约4.39亿年前），对于记录脊椎动物的最初多样化非常重要。这些分析补充了越来越多的化石证据，并支持有颌脊椎动物更早出现是奥陶纪生物大分化事件（大约4.85-4.45亿年前）的一部分。
据悉，下颌牙和牙列是有颌脊椎动物的特征，也是古生代软骨鱼类和骨鱼类的祖先首先获得的。目前，化石记录显示，志留纪后期（约4.25亿年前）是有颌类牙齿出现的最早日期，也是随后的泥盆纪下颚牙齿生长和替换机制的演变日期。
附：英文原文
Title: The oldest gnathostome teeth
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: Mandibular teeth and dentitions are features of jawed vertebrates that were first acquired by the Palaeozoic ancestors1,2,3 of living chondrichthyans and osteichthyans. The fossil record currently points to the latter part of the Silurian period4,5,6,7 (around 425million years ago) as a minimum date for the appearance of gnathostome teeth and to the evolution of growth and replacement mechanisms of mandibular dentitions in the subsequent Devonian period2,8,9,10. Here we provide, to our knowledge, the earliest direct evidence for jawed vertebrates by describing Qianodus duplicis, a new genus and species of an early Silurian gnathostome based on isolated tooth whorls from Guizhou province, China. The whorls possess non-shedding teeth arranged in a pair of rows that demonstrate a number of features found in modern gnathostome groups. These include lingual addition of teeth in offset rows and maintenance of this patterning throughout whorl development. Our data extend the record of toothed gnathostomes by 14million years from the late Silurian into the early Silurian (around 439million years ago) and are important for documenting the initial diversification of vertebrates. Our analyses add to mounting fossil evidence that supports an earlier emergence of jawed vertebrates as part of the Great Ordovician Biodiversification Event (approximately 485–445 million years ago).
DOI: 10.1038/s41586-022-05166-2
Source: https://www.nature.com/articles/s41586-022-05166-2
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
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
