Large deadfalls of the ʻginsuʼ shark Cretoxyrhina mantelli (Agassiz, 1835) (Neoselachii, Lamniformes) from the Upper Cretaceous of northeastern Italy

Autor(en)
Jacopo Amalfitano, Luca Giusberti, Eliana Fornaciari, Fabio Marco Dalla Vecchia, Valeria Luciani, Jürgen Kriwet, Giorgio Carnevale
Abstrakt

Cretoxyrhina mantelli was a large pelagic lamniform shark geographically widespread during the Late Cretaceous, and well known because of several nearly complete skeletons from the Western Interior Seaway of North America. Here we report 15 partial skeletons belonging to lamniform sharks from the ‘lastame’ lithozone of the Upper Cretaceous Scaglia Rossa Formation of the Lessini Mountains (northeastern Italy). Seven partial but articulated skeletons include tooth sets that allow a confident attribution to Cretoxyrhina mantelli based on dental morphologies. We review the taxonomic history of C. mantelli, evidencing that the taxon was erected by Agassiz (1835) and tracing back four of the original syntypes. Based on calcareous plankton biostratigraphy, the rock in which the Italian skeletal remains are embedded is constrained to the middle-upper Turonian. Total length estimates of the specimens suggest that the sample includes the largest specimen of Cretoxyrhina mantelli (615–650 cm estimated total length) known to date. The placoid scale morphology indicates that C. mantelli most likely was a fast swimmer with a similar ecology as the extant white shark, Carcharodon carcharias. The associated skeletal elements of the specimens represent large chondrichthyan deadfalls and the cadavers decayed on the seafloor where they remained exposed for several months, as indicated by bioerosional traces, some of which are interpreted as a product of bone-eating worm activities and other bioerosional traces with Gastrochaenolites-like structure. The Cretoxyrhina mantelli remains described herein provide new information about the ʻlastameʼ vertebrate assemblage, which seemingly was strongly dominated by chondrichthyans, especially lamniform sharks.

Organisation(en)
Institut für Paläontologie
Externe Organisation(en)
Università degli Studi di Padova, Universitá degli studi di Ferrara, Universitat Autònoma de Barcelona , Università degli Studi di Torino
Journal
Cretaceous Research
Band
98
Seiten
250-275
Anzahl der Seiten
26
ISSN
0195-6671
DOI
https://doi.org/10.1016/j.cretres.2019.02.003
Publikationsdatum
06-2019
Peer-reviewed
Ja
ÖFOS 2012
106054 Zoologie, 105118 Paläontologie
Schlagwörter
ASJC Scopus Sachgebiete
Palaeontology
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/3452f5e7-fc9a-4937-bebf-324503b90a04