Revision of Erpetosuchus (Archosauria: Pseudosuchia) and new erpetosuchid material from the Late Triassic ‘Elgin Reptile’ fauna based on µCT scanning techniques

Research output: Contribution to journalArticlepeer-review

Authors

  • Davide Foffa
  • Sterling Nesbitt
  • Stig Walsh
  • Paul M. Barrett
  • Stephen L. Brusatte
  • Nicholas Fraser

Colleges, School and Institutes

External organisations

  • University of Edinburgh, The

Abstract

The Late Triassic fauna of the Lossiemouth Sandstone Formation (LSF) from the Elgin area, Scotland, has been pivotal in expanding our understanding of Triassic terrestrial tetrapods. Frustratingly, due to their odd preservation, interpretations of the Elgin Triassic specimens have relied on destructive moulding techniques, which only provide incomplete, and potentially distorted, information. Here, we show that micro-Computed Tomography (µCT) could revitalise the study of this important assemblage.
We describe a long-neglected specimen that was originally identified as a pseudosuchian archosaur Ornithosuchus woodwardi. µCT scans revealed dozens of bones belonging to at least two animals: a small-bodied pseudosuchian, and a specimen of the procolophonid Leptopleuron lacertinum. The pseudosuchian skeleton possesses a combination of characters that are unique to the clade Erpetosuchidae. As a basis for investigating the phylogenetic relationships of this new specimen, we reviewed the anatomy, taxonomy and systematics of other erpetosuchid specimens from the LSF (all previously referred to Erpetosuchus). Unfortunately, due to the differing representation of the skeleton in the available Erpetosuchus specimens, we cannot determine whether the erpetosuchid specimen we describe here belongs to E. granti (to which we show it is closely related) or if it represents a distinct new taxon. Nevertheless, our results shed light on rarely preserved details of erpetosuchid anatomy. Finally, the unanticipated new information extracted from both previously studied and neglected specimens suggests that fossil remains may be much more widely distributed in the Elgin quarries than previously recognized, and that the richness of the LSF might have been underestimated.

Details

Original languageEnglish
JournalEarth and Environmental Science Transactions of the Royal Society of Edinburgh
Early online date6 Nov 2020
Publication statusE-pub ahead of print - 6 Nov 2020