New interpretation of the cranial osteology of the Early Cretaceous turtle Arundelemys dardeni (Paracryptodira) based on a CT-based re-evaluation of the holotype

PeerJ

article

Serjoscha W. Evers¹  Yann Rollot¹  Walter G. Joyce¹ 

[1] Department of Geosciences, University of Fribourg

关键词: Testudines;    Paracryptodira;    Baenidae;    Cranial scutes;    Turtles;    CT-scan;    Turtle evolution;    Cranial anatomy;   

DOI  :  10.7717/peerj.11495

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Arundelemys dardeni is an Early Cretaceous paracryptodire known from a single, incomplete, but generally well-preserved skull. Phylogenetic hypotheses of paracryptodires often find Arundelemys dardeni as an early branching baenid. As such, it has a central role in understanding the early evolution of the successful clade Baenidae, which survived the Cretaceous–Paleogene mass extinction, as well as the diversification of Paracryptodira into its subclades, which recent research suggests to perhaps include helochelydrids, compsemydids, pleurosternids, and baenids. Computer tomography scans of the holotype material that were produced for the initial description of Arundelemeys dardeni reveal several errors in the initial anatomical description of the species, which we correct based on element-by-element segmentation. In addition, we provide entirely novel anatomical information, including descriptions of several previously undescribed cranial bones, the endosseous labyrinth, and the cranial scutes, the latter of which are unknown for most paracryptodires. We provide an interpretation of cranial scutes which homologizes the scutes of Arundelemys dardeni with those of other stem turtles.

【 授权许可】

CC BY