A palaeoequatorial ornithischian and new constraints on early dinosaur diversification

Research output: Contribution to journalArticlepeer-review

Authors

  • Paul M. Barrett
  • Roland Mundil
  • Torsten M. Scheyer
  • Randall B. Irmis
  • Marcelo R. Sánchez-Villagra

Colleges, School and Institutes

External organisations

  • Ludwig-Maximilians Universität Munchen
  • Berkeley Geochronology Center
  • University of Zurich
  • Natural History Museum of Utah
  • University of Utah

Abstract

Current characterizations of early dinosaur evolution are incomplete: Existing palaeobiological and phylogenetic scenarios are based on a fossil record dominated by saurischians and the implications of the early ornithischian record are often overlooked. Moreover, the timings of deep phylogenetic divergences within Dinosauria are poorly constrained owing to the absence of a rigorous chronostratigraphical framework for key Late Triassic-Early Jurassic localities. A new dinosaur from the earliest Jurassic of the Venezuelan Andes is the first basal ornithischian recovered from terrestrial deposits directly associated with a precise radioisotopic date and the first-named dinosaur from northern South America. It expands the early palaeogeographical range of Ornithischia to palaeoequatorial regions, an area sometimes thought to be devoid of early dinosaur taxa, and offers insights into early dinosaur growth rates, the evolution of sociality and the rapid tempo of the global dinosaur radiation following the end-Triassic mass extinction, helping to underscore the importance of the ornithischian record in broad-scale discussions of early dinosaur history.

Details

Original languageEnglish
Article number20141147
JournalRoyal Society of London. Proceedings B. Biological Sciences
Volume281
Issue number1791
Publication statusPublished - 6 Aug 2014

Keywords

  • End-Triassic extinction, Lower Jurassic, Ornithischia, Osteohistology, Palaeobiogeography