Evolutionary trends of the conserved neurocranium shape in angel sharks (Squatiniformes, Elasmobranchii)

Author(s)
Faviel Alejandro López Romero, Sebastian Stumpf, Cathrin Pfaff, Giuseppe Marramà, Jürgen Kriwet
Abstract

Elasmobranchii (i.e., sharks, skates, and rays) forms one of the most diverse groups of marine predators. With a fossil record extending back into the Devonian, several modifications in their body plan illustrate their body shape diversity through time. The angel sharks, whose fossil record dates back to the Late Jurassic, some 160 Ma, have a dorsoventrally flattened body, similar to skates and rays. Fossil skeletons of this group show that the overall morphology was well established earlier in its history. By examining the skull shape of well-preserved fossil material compared to extant angel
sharks using geometric morphometric methods, within a phylogenetic framework, we were able to determine the conservative skull shape among angel sharks with a high degree of integration. The morphospace occupation of extant angel sharks is rather restricted, with extensive overlap. Most of the differences in skull shape are related to their geographic distribution patterns. We found higher levels of disparity in extinct forms, but lower ones in extant species. Since angel sharks display a highly
specialized prey capture behaviour, we suggest that the morphological integration and biogeographic processes are the main drivers of their diversity, which might limit their capacity to display higher disparities since their origin.

Organisation(s)
Department of Palaeontology
External organisation(s)
University of Turin
Journal
Scientific Reports
Volume
10
Pages
1-13
No. of pages
13
ISSN
2045-2322
DOI
https://doi.org/10.1038/s41598-020-69525-7
Publication date
07-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
106012 Evolutionary research, 105118 Palaeontology
Keywords
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/750caed2-03c4-415b-9c63-20d0dde1ab9d