The affinities and ecology of Triassic ichthyosaurs

Research Article| April 01, 1990 The affinities and ecology of Triassic ichthyosaurs JUDY A. MASSARE; JUDY A. MASSARE 1Department of Geological Sciences, University of Rochester, Rochester, New York 14627 Search for other works by this author on: GSW Google Scholar JACK M. CALLAWAY JACK M. CALLAWAY 1Department of Geological Sciences, University of Rochester, Rochester, New York 14627 Search for other works by this author on: GSW Google Scholar Author and Article Information JUDY A. MASSARE 1Department of Geological Sciences, University of Rochester, Rochester, New York 14627 JACK M. CALLAWAY 1Department of Geological Sciences, University of Rochester, Rochester, New York 14627 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1990) 102 (4): 409–416. https://doi.org/10.1130/0016-7606(1990)102<0409:TAAEOT>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation JUDY A. MASSARE, JACK M. CALLAWAY; The affinities and ecology of Triassic ichthyosaurs. GSA Bulletin 1990;; 102 (4): 409–416. doi: https://doi.org/10.1130/0016-7606(1990)102<0409:TAAEOT>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The resolution of the problem of ichthyosaurian affinities has been complicated and prolonged by an emphasis on the morphology of Jurassic ichthyosaurs, some 30 to 40 m.y. younger than the earliest known species. Morphology of the skull and axial skeleton of Triassic ichthyosaurs is the key to resolving the problem. The ichthyosaurs are included here in the Subclass Diapsida on the basis of skull roof and palatal features. Within the Diapsida, ichthyosaurs appear to be most closely related to the Younginiformes of the Infraclass Lepidosauromorpha, with which they may have shared a common ancestor.Triassic ichthyosaurs were considerably different ecologically from their Jurassic descendants. Many Triassic ichthyosaurs were longer bodied and had long, broad tails in contrast to the deep, streamlined bodies and lunate tails of Jurassic species. As a result, Triassic ichthyosaurs probably tended to be ambush predators, whereas Jurassic ichthyosaurs were mainly pursuit predators. Early ichthyosaurs may have been more generalized in their prey preference, as suggested by heterodonty in many Early and Middle Triassic species. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.