Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia.
Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia.
PeerJ. 2022 Nov 4;10:e14308. doi: 10.7717/peerj.14308. eCollection 2022.
Abnormal trilobites present insight into how arthropods with fully biomineralised exoskeletons recovered from injuries, genetic malfunctions, and pathologies. Records of abnormal Silurian trilobites in particular show an abundance of specimens with teratologies and a limited record of injuries. Here we expand the record of abnormal Silurian trilobites by presenting seven new abnormal specimens of from the early Silurian (Llandovery, Telychian) Cotton Formation, New South Wales. We use these specimens to illustrate novel evidence for asymmetric distribution of pleural thoracic spine bases. These abnormal bases likely reflect genetic complications, resulting in morphologies that would unlikely have aided the fitness of abnormal individuals. In considering records of malformed Silurian trilobites more broadly, we propose that the largest trilobites may have been prey at this time. This indicates a possible change in the trophic position of trilobites when compared to Cambrian and Ordovician palaeoecosystems.
异常三叶虫为完全生物矿化外骨骼的节肢动物如何从损伤、遗传功能障碍和病变中恢复提供了深入了解。特别是志留纪异常三叶虫的记录显示出大量具有畸形的标本，而受伤的记录有限。在这里，我们通过展示来自新南威尔士州早志留世（兰多维利世，泰利奇亚世）棉花组的七个新的异常三叶虫来扩展异常志留纪三叶虫的记录。我们使用这些标本来说明胸肋刺基部不对称分布的新证据。这些异常的基部可能反映了遗传并发症，导致的形态不太可能有助于异常个体的适应性。在更广泛地考虑畸形志留纪三叶虫的记录时，我们提出此时最大的三叶虫可能是猎物。与寒武纪和奥陶纪古生态系统相比，这表明三叶虫的营养位置可能发生了变化。
