Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Johan Lindgren

Johan Lindgren

Senior lecturer

Johan Lindgren

A fishy mosasaur: the axial skeleton of Plotosaurus (Reptilia, Squamata) reassessed

Author

  • Johan Lindgren
  • John W. M. Jagt
  • Michael W. Caldwell

Summary, in English

The concept of convergence, that is, how unrelated animals independently evolve similar morphological traits, is a fundamental aspect of evolution. Hitherto, the Mesozoic ichthyosaurs were regarded as the sole obligate marine reptiles that achieved a fully streamlined body and a semilunate tail fluke. However, analyses of vertebral centrum morphometrics and process orientation have revealed that a subsequent clade of secondarily aquatic reptiles, the mosasaurs (here exemplified by the advanced, mid-Maastrichtian mosasaurine Plotosaurus), had developed a deep, fusiform body and a probable pursuit-predatory behaviour by the time of their sudden extinction at the Cretaceous-Paleogene boundary. Stringent physical constraints and selection pressures, imposed by the surrounding water, probably were responsible for this spectacular example of large-scale evolutionary convergence.

Department/s

  • Lithosphere and Biosphere Science

Publishing year

2007

Language

English

Pages

153-160

Publication/Series

Lethaia

Volume

40

Issue

2

Document type

Journal article

Publisher

Taylor & Francis

Topic

  • Geology

Keywords

  • tail stock
  • tail fin
  • surface
  • propulsive
  • Plotosaurus
  • Mosasauridae
  • displacement unit
  • hypocercal

Status

Published

ISBN/ISSN/Other

  • ISSN: 0024-1164