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

Manuel Amadori (Corresponding author), Jacopo Amalfitano, Luca Giusberti, Eliana Fornaciari, Giorgio Carnevale, Jürgen Kriwet

Publications: Contribution to journalArticlePeer Reviewed

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.
Original languageEnglish
Article numbere10167
Number of pages35
JournalPeerJ
Volume8
DOIs
Publication statusPublished - 24 Nov 2020

Austrian Fields of Science 2012

  • 105118 Palaeontology

Keywords

  • BASIN
  • DENTITION
  • Durophagy
  • Fossil sharks
  • Heterodonty
  • MAMMILLARIS
  • MORPHOLOGY
  • NOMENCLATURE
  • NORTHEASTERN
  • PTYCHODONTIDAE
  • STANDARDIZED DIET COMPOSITIONS
  • TOOTH SET
  • TROPHIC LEVELS
  • Taxonomy
  • Upper Cretaceous
  • Veneto region

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