Redescription of Phymolepis cuifengshanensis (Antiarcha: Yunnanolepididae) using high-resolution computed tomography and new insights into anatomical details of the endocranium in antiarchs

Background. Yunnanolepidoids constitute either the basal-most consecutive segments or the most primitive clade of antiarchs, a highly diversified jawed vertebrate group from the Silurian and Early Devonian periods. Although the general morphology of yunnanolepidoids is well established, their endocranial features remain largely unclear, thus hindering our further understanding of antiarch evolution, and early gnathostome evolution. Phymolepis cuifengshanensis, a yunnanolepidoid from the Early Devonian of southwestern China, is re-described in detail to reveal the information on endocranial anatomy and additional morphological data of head and trunk shields. Methods. We scanned the material of P. cuifengshanensis using high-resolution computed tomography and generated virtual restorations to show the internal morphology of its dermal shield. The dorsal aspect of endocranium in P. cuifengshanensis was therefore inferred. The phylogenetic analysis of antiarchs was conducted based on a revi...

研究背景：
云南骨甲鱼类（Yunnanolepidoids）要么是反甲鱼类（antiarchs，一类源自志留纪与早泥盆世的高度多样化有颌脊椎动物类群）最基部的连续演化支系，或是其最原始的演化类群。尽管云南骨甲鱼类的整体形态特征已得到充分阐明，但其颅内解剖结构特征仍大多未被探明，这阻碍了学界对反甲鱼类演化以及早期有颌脊椎动物演化的进一步认知。本研究对产自中国西南早泥盆世的云南骨甲鱼类物种翠峰山瘤鳞鱼（Phymolepis cuifengshanensis）进行了详细的重新描述，以揭示其颅内解剖结构信息以及头部与躯干盾的额外形态学数据。
研究方法：
我们采用高分辨率计算机断层扫描（high-resolution computed tomography）技术对翠峰山瘤鳞鱼的标本进行扫描，并构建虚拟复原模型以展示其真皮盾的内部形态结构。借此，我们得以推断翠峰山瘤鳞鱼颅内结构的背侧形态。针对反甲鱼类的系统发育分析基于一项修订（原文未完结）得以开展。