
Johan Lindgren
Universitetslektor

A fishy mosasaur: the axial skeleton of Plotosaurus (Reptilia, Squamata) reassessed
Författare
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.
Avdelning/ar
- Berggrundsgeologi
Publiceringsår
2007
Språk
Engelska
Sidor
153-160
Publikation/Tidskrift/Serie
Lethaia
Volym
40
Issue
2
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Taylor & Francis
Ämne
- Geology
Nyckelord
- tail stock
- tail fin
- surface
- propulsive
- Plotosaurus
- Mosasauridae
- displacement unit
- hypocercal
Aktiv
Published
ISBN/ISSN/Övrigt
- ISSN: 0024-1164