Heterodonty and ontogenetic shift dynamics in the dentition of the tiger shark Galeocerdo cuvier (Chondrichthyes, Galeocerdidae)

Julia Türtscher, Patrick Leopold Jambura, Faviel Alejandro López Romero, R. Kindlimann, Keichii Sato, Taketeru Tomita, Jürgen Kriwet

Publications: Contribution to journalArticlePeer Reviewed

Abstract

The lifelong tooth replacement in elasmobranch fishes (sharks, rays and skates) has
led to the assemblage of a great number of teeth from fossil and extant species, rendering tooth morphology an important character for taxonomic descriptions, analysing phylogenetic interrelationships and deciphering their evolutionary history (e.g. origination, divergence, extinction). Heterodonty (exhibition of different tooth morphologies) occurs in most elasmobranch species and has proven to be one of the main challenges for these analyses. Although numerous shark species are discovered and described every year, detailed descriptions of tooth morphologies and heterodonty patterns are lacking or are only insufficiently known for most species. Here, we use landmark-based 2D geometric morphometrics on teeth of the tiger shark Galeocerdo cuvier to analyse and describe dental heterodonties among four different ontogenetic stages ranging from embryo to adult. Our results reveal rather gradual and subtle ontogenetic shape changes, mostly characterized by increasing size and complexity of the teeth. We furthermore provide the first comprehensive description of embryonic dental morphologies in tiger sharks. Also, tooth shapes of tiger sharks in different ontogenetic stages are re-assessed and depicted in detail. Finally, multiple cases of tooth file reversal are described. This study, therefore, contributes to our knowledge of dental traits across ontogeny in the extant tiger shark G. cuvier and provides a baseline for further morphological and genetic studies on the dental variation in sharks. Therefore, it has the potential to assist elucidating the underlying developmental and evolutionary processes behind the vast dental diversity observed in elasmobranch fishes today and in deep time.
Original languageEnglish
Pages (from-to)372-392
Number of pages21
JournalJournal of Anatomy
Volume241
Issue number2
Early online date15 Apr 2022
DOIs
Publication statusPublished - Aug 2022

Austrian Fields of Science 2012

  • 105118 Palaeontology

Keywords

  • CARCHARHINIFORMES
  • DIET
  • ELASMOBRANCHII
  • FEEDING ECOLOGY
  • GREAT WHITE SHARK
  • MORPHOLOGY
  • REPRODUCTIVE-BIOLOGY
  • SEX
  • TEETH
  • TOOTH PATTERN-REVERSAL
  • elasmobranch
  • embryonic dentition
  • geometric morphometrics
  • ontogenetic trajectory
  • teeth
  • tooth pattern reversal
  • ontogenetic trajectory, teeth

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