The Italian record of the Cretaceous shark, <i>Ptychodus latissimus</i> Agassiz, 1835 (Chondrichthyes; Elasmobranchii)

Author(s)
Manuel Amadori, Jacopo Amalfitano, Luca Giusberti, Eliana Fornaciari, Giorgio Carnevale, Jürgen Kriwet
Abstract

Associated and isolated teeth of the extinct elasmobranch Ptychodus latissimus Agassiz, 1835 from the Upper Cretaceous Scaglia Rossa pelagic limestone of northern Italy are described and discussed here in detail for the first time. The dentition of this widely distributed species consists of low-crowned molariform teeth that exhibit marked and strong occlusal ornamentations suitable for crushing hard-shelled prey. The associated tooth sets and isolated teeth analyzed here are heterogeneous in size and crown outline, but unambiguously belong to a single species. Re-examination of this Italian material consisting of ca. 30 specimens mostly coming from historical collections allows for a rigorous assessment of the intraspecific variability of P. latissimus, including the identification of three different tooth “morphotypes” based on their positions within the jaws. The relatively flat crowns and occlusal sharp and thick ridges indicate a high adaptation for crushing hard-shelled prey in P. latissimus indicating that the durophagous adaptations of this species were certainly more pronounced than in all other species of Ptychodus. We hypothesize that P. latissimus was a third-level predator occupying habitats with abundant thickshelled prey, such as inoceramid bivalves and ammonites.

Organisation(s)
Department of Palaeontology
External organisation(s)
University of Padova, University of Turin
Journal
PeerJ
Volume
8
No. of pages
35
ISSN
2167-8359
DOI
https://doi.org/10.7717/peerj.10167
Publication date
11-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
General Agricultural and Biological Sciences, General Biochemistry,Genetics and Molecular Biology, General Neuroscience
Portal url
https://ucrisportal.univie.ac.at/en/publications/f72fcad4-6e24-4e42-a20c-e9dae8b18d8c