Analysis of dental insertion angles in the sand tiger shark, Carcharias taurus (Chondrichthyes: Lamniformes)

Lucifora L.O., Menni R.C., Escalante A.H.

Date de parution: février 2001
Volume: 25
Number: 1
Pagination: 023-031
Editeur: Société Française d’Ichtyologie
doi: https://doi.org/10.26028/cybium/2001-251-002
Résumé

Differences in insertion angles of each tooth type of Carcharias taurus are described and analyzed within a functional framework. Upper anterior teeth show a more pronounced inward inclination than upper lateral and lower anterior ones that would be related to initial puncturing of prey. Lower anterior teeth have an outward inclination, probably related to a function of initial prey grasping by these teeth while the upper anteriors puncture prey. The upper lateral teeth are more inclined than the lower lateral. Upper and lower lateral teeth would be adapted to hold prey. A ventral inclination of the anterior part of the palatoquadrate is present in C. taurus, and it is likely to facilitate the puncturing work of the upper anterior and to enhance the patchiness of these teeth. We also report some dental anomalies such as intermediate tooth reversal, reduced first and second lower anterior teeth, presence of hook-like anterior and lateral teeth, and the absence of a lower lateral tooth. These latter two anomalies are described for the first time in C. taurus. Our results agree with previously published interpretations based on tooth shape. The results here presented can be considered as a working hypothesis for future experimental research.

Mots-clés: Carcharias taurus - Elasmobranchii - Feeding - Mechanics - Morphology - Teeth
PDF visible pour tous