脊椎动物牙齿的起源和感觉外骨骼的进化，这一成果由芝加哥大学Neil H. Shubin研究小组经过不懈努力而取得。2025年5月21日出版的《自然》杂志发表了这项成果。

为了解决这一争议并了解牙齿组织的起源，该团队同步扫描了各种已灭绝和现存的脊椎动物和无脊椎动物的外骨骼。该课题组发现Anatolepis的小管被误认为是牙本质小管，而不是代表无齿节肢动物的感觉结构。同步加速器扫描显示齿状齿和感觉结构之间的深层超微结构相似性也延伸到确定的脊椎动物组织。奥陶系脊椎动物尖齿外齿具有与无脊椎动物感受器形态趋同的大牙本质小管。免疫荧光分析显示，现存软骨鱼和硬骨鱼的外齿保留了广泛的神经支配，提示其具有类似牙齿的感觉功能。这些会聚和神经支配的模式揭示了牙本质在早期脊椎动物的外骨骼中作为一种感觉组织进化而来，这种功能保留在现代脊椎动物的牙齿中。中奥陶世的化石现在是已知最古老的脊椎动物牙齿组织的证据。

据介绍，最早的牙齿祖先和组织牙质记录是一种早期脊椎动物的新奇事物，被鉴定为Anatolepis heintzi的寒武纪化石碎片所代表，这是有争议的。Anatolepis的外骨骼具有典型的牙本质小管，这促使他们被解释为牙齿的第一个前身，被称为齿状齿。关于Anatolepis是否是一种合法的脊椎动物的争论已经出现，因为成像的限制和缺乏可比较的外骨骼组织。

附：英文原文

Title: The origin of vertebrate teeth and evolution of sensory exoskeletons

Author: Haridy, Yara, Norris, Sam C. P., Fabbri, Matteo, Nanglu, Karma, Sharma, Neelima, Miller, James F., Rivers, Mark, La Riviere, Patrick, Vargas, Phillip, Ortega-Hernndez, Javier, Shubin, Neil H.

Issue&Volume: 2025-05-21

Abstract: The earliest record of tooth antecedents and the tissue dentine1,2, an early-vertebrate novelty, has been controversially represented by fragmentary Cambrian fossils identified as Anatolepis heintzi3,4,5. Anatolepis exoskeletons have the characteristic tubules of dentine that prompted their interpretation as the first precursors of teeth3, known as odontodes. Debates over whether Anatolepis is a legitimate vertebrate6,7,8 have arisen because of limitations in imaging and the lack of comparative exoskeletal tissues. Here, to resolve this controversy and understand the origin of dental tissues, we synchrotron-scanned diverse extinct and extant vertebrate and invertebrate exoskeletons. We find that the tubules of Anatolepis have been misidentified as dentine tubules and instead represent aglaspidid arthropod sensory sensilla structures9,10. Synchrotron scanning reveals that deep ultrastructural similarities between odontodes and sensory structures also extend to definitive vertebrate tissues. External odontodes of the Ordovician vertebrate Eriptychius11,12,13 feature large dentine tubules1 that are morphologically convergent with invertebrate sensilla. Immunofluorescence analysis shows that the external odontodes of extant chondrichthyans and teleosts retain extensive innervation suggestive of a sensory function akin to teeth14,15,16. These patterns of convergence and innervation reveal that dentine evolved as a sensory tissue in the exoskeleton of early vertebrates, a function retained in modern vertebrate teeth16. Middle-Ordovician fossils now represent the oldest known evidence for vertebrate dental tissues.

DOI: 10.1038/s41586-025-08944-w

Source: https://www.nature.com/articles/s41586-025-08944-w