Tooth development and histology patterns in lamniform sharks (Elasmobranchii, Lamniformes) revisited

Author(s)
Lisa Schnetzer, Cathrin Pfaff, Jürgen Kriwet
Abstract

The dentition of lamniforme sharks exhibits several characters that have been used extensively to resolve the phylogenetic relationships of extant taxa, yet some uncertainties remain. Also, the development of different teeth of a tooth file within the jaws of most extant lamniforms has not been documented to date. High-resolution micro-computed tomography is used here to re-evaluate the importance of two dental characters within the order Lamniformes, which were considered not to be phylogenetically informative, the histotype and the number of teeth per tooth file. Additionally, the development and mineralization patterns of the teeth of the two osteodont lamniforms Lamna nasus and Alopias superciliosus were compared. We discuss the importance of these dental characters for phylogenetic interpretations to assess the quality of these characters in resolving lamniform relationships. The dental characters suggest that (1) Lamniformes are the only modern-level sharks exhibiting the osteodont histotype, (2) the osteodont histotype in lamniform sharks is a derived state in modern-level sharks (Elasmobranchii), (3) the osteodont type, conversely is convergently achieved when the clade Chondrichthyes is considered and thus might comprise a functional rather than a phylogenetic signal, and (4) there is an increase in the number of teeth per file throughout lamniform phylogeny. Structural development of the teeth of L. nasus and A. superciliosus is congruent with a previous investigation of the lamniform shark Carcharodon carcharias. J. Morphol. 277:1584–1598, 2016.

Organisation(s)
Department of Palaeontology
External organisation(s)
University of Vienna
Journal
Journal of Morphology
Volume
277
Pages
1584-1598
No. of pages
15
ISSN
0362-2525
DOI
https://doi.org/10.1002/jmor.20597
Publication date
12-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
Animal Science and Zoology, Developmental Biology
Portal url
https://ucrisportal.univie.ac.at/en/publications/8262a989-5416-4766-aff3-cbde909fa02d