A skeleton from the Middle Jurassic of Scotland illuminates an earlier origin of large pterosaurs

Curr Biol. 2022 Mar 28;32(6):1446-1453.e4. doi: 10.1016/j.cub.2022.01.073. Epub 2022 Feb 22.

Abstract

Pterosaurs were the first vertebrates to evolve flight1,2 and include the largest flying animals in Earth history.3,4 While some of the last-surviving species were the size of airplanes, pterosaurs were long thought to be restricted to small body sizes (wingspans ca. <1.8-1.6 m) from their Triassic origins through the Jurassic, before increasing in size when derived long-skulled and short-tailed pterodactyloids lived alongside a diversity of birds in the Cretaceous.5 We report a new spectacularly preserved three-dimensional skeleton from the Middle Jurassic of Scotland, which we assign to a new genus and species: Dearc sgiathanach gen. et sp. nov. Its wingspan is estimated at >2.5 m, and bone histology shows it was a juvenile-subadult still actively growing when it died, making it the largest known Jurassic pterosaur represented by a well-preserved skeleton. A review of fragmentary specimens from the Middle Jurassic of England demonstrates that a diversity of pterosaurs was capable of reaching larger sizes at this time but have hitherto been concealed by a poor fossil record. Phylogenetic analysis places D. sgiathanach in a clade of basal long-tailed non-monofenestratan pterosaurs, in a subclade of larger-bodied species (Angustinaripterini) with elongate skulls convergent in some aspects with pterodactyloids.6 Far from a static prologue to the Cretaceous, the Middle Jurassic was a key interval in pterosaur evolution, in which some non-pterodactyloids diversified and experimented with larger sizes, concurrent with or perhaps earlier than the origin of birds. VIDEO ABSTRACT.

Keywords: Isle of Skye; Jurassic; Scotland; evolution; fossil; histology; paleontology; phylogeny; pterosaur; wingspan.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review
  • Video-Audio Media

MeSH terms

  • Animals
  • Biological Evolution
  • Birds
  • Body Size
  • Dinosaurs* / anatomy & histology
  • Fossils*
  • Phylogeny
  • Skull