Colobops: a juvenile rhynchocephalian reptile (Lepidosauromorpha), not a diminutive archosauromorph with an unusually strong bite

Research output: Contribution to journalArticlepeer-review


  • Torsten M. Scheyer
  • Stephan Spiekman
  • Hans-Dieter Sues
  • Martin Ezcurra
  • Marc Jones

External organisations

  • Paläontologisches Institut und Museum, Universität Zürich


Correctly identifying taxa at the root of major clades or the oldest clade-representatives is critical for meaningful interpretations of evolution. A small, partially crushed skull from the Late Triassic (Norian) of Connecticut, USA, originally described as an indeterminate rhynchocephalian saurian, was recently named Colobops noviportensis and reinterpreted as sister to all remaining Rhynchosauria, one of the earliest and globally distributed groups of herbivorous reptiles. It was also interpreted as having an exceptionally reinforced snout and powerful bite based on an especially large supratemporal fenestra. Here, after a re-analysis of the original scan data, we show that the skull was strongly dorsoventrally compressed postmortem, with most bones out of life position. The cranial anatomy is consistent with that of other rhynchocephalian lepidosauromorphs, not rhynchosaurs. The ‘reinforced snout’ region and the ‘exceptionally enlarged temporal region’ are preservational artefacts and not exceptional among clevosaurid rhynchocephalians. Colobops is thus not a key taxon for understanding diapsid feeding apparatus evolution.


Original languageEnglish
Article number192179
Number of pages14
JournalRoyal Society Open Science
Issue number3
Publication statusPublished - 25 Mar 2020


  • Diapsida, feeding apparatus, Colobops, noviportensis, Rhynchocephalia, Triassic