A new and large monofenestratan reveals the evolutionary transition to the pterodactyloid pterosaurs

Bruce and Rene Lauer have done it again… groundbreaking paleontological research.  This time it’s a new pterosaur, Skiphosoura bavarica, from the Jurassic of Germany.  The lead author is David Hone with Adam Fitch, Stefan Selzer, and the Lauers.  The paper is Open Access and was published in the journal Current Biology.

Highlights

  • A new pterosaur, Skiphosoura bavarica, is named from the Jurassic of Germany
  • The specimen is much larger than other known forms and is preserved in three dimensions
  • The Skiphosoura helps document the transition from early pterosaurs to the pterodactyloids
  • The tail is short but retains the supporting structures of earlier forms

Summary

For over a century, there was a major gap in our understanding of the evolution of the flying Mesozoic reptiles, the pterosaurs, with a major morphological gap between the early forms and the derived pterodactyloids.1 Recent discoveries have found a cluster of intermediate forms that have the head and neck of the pterodactyloids but the body of the early grade,2 yet this still leaves fundamental gaps between these intermediates and both earlier and more derived pterosaurs. Here, we describe a new and large Jurassic pterosaur, Skiphosoura bavarica gen. et sp. nov., preserved in three dimensions, that helps bridge the gap between current intermediate pterosaurs and the pterodactyloids. A new phylogeny shows that there is a general progression of key characteristics of increasing head size, increasing length of neck and wing metacarpal, modification to the fifth toe that supports the rear wing membrane, and gradual reduction in tail length and complexity from earlier pterosaurs into the first pterodactyloids. This also shows a clear evolution of the increasing terrestrial competence of derived pterosaurs. Furthermore, this closes gaps between the intermediates and their ancestors and descendants, and it firmly marks the rhamphorhynchines and ctenochasmatid clades as, respectively, being the closest earliest and latest groups to this succession of transitional forms.

Leave a Reply

Discover more from Earth Science Club of Northern Illinois

Subscribe now to keep reading and get access to the full archive.

Continue reading