Monday, April 28, 2014

[Paleontology • 2014] Kryptodrakon progenitor • The Earliest Pterodactyloid (Pterosauria: Pterodactyloidea) from the terrestrial Middle-Upper Jurassic boundary of Northwest China and the Origin of the Group

Kryptodrakon progenitor
Andres, Clark & Xu, 2014
  Illustration: Emily M. Eng  

• We report the earliest and basalmost pterodactyloid pterosaur
• The Pterodactyloidea originated in terrestrial environments
• Pterosaur evolution is highly correlated with paleoenvironment
• Pterosaurs were adapted to the environments in which they were preserved

The pterosaurs were a diverse group of Mesozoic flying reptiles that underwent a body plan reorganization, adaptive radiation, and replacement of earlier forms midway through their long history, resulting in the origin of the Pterodactyloidea, a highly specialized clade containing the largest flying organisms. The sudden appearance and large suite of morphological features of this group were suggested to be the result of it originating in terrestrial environments, where the pterosaur fossil record has traditionally been poor, and its many features suggested to be adaptations to those environments. However, little evidence has been available to test this hypothesis, and it has not been supported by previous phylogenies or early pterodactyloid discoveries. We report here the earliest pterosaur with the diagnostic elongate metacarpus of the Pterodactyloidea, Kryptodrakon progenitor, gen. et sp. nov., from the terrestrial Middle-Upper Jurassic boundary of Northwest China. Phylogenetic analysis confirms this species as the basalmost pterodactyloid and reconstructs a terrestrial origin and a predominantly terrestrial history for the Pterodactyloidea. Phylogenetic comparative methods support this reconstruction by means of a significant correlation between wing shape and environment also found in modern flying vertebrates, indicating that pterosaurs lived in or were at least adapted to the environments in which they were preserved.

A diagram shows the fragmentary remains of Kryptodrakon progenitor.
The skeletal outline is Pterodactylus antiques
 Illustration | Brian Andres

Andres, B.; Clark, J.; Xu, X. 2014. The Earliest Pterodactyloid and the Origin of the Group. Current Biology. Forthcoming. doi:

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