Tuesday, August 14, 2018

[Paleontology • 2018] Caelestiventus hanseni • extends the Desert-dwelling Pterosaur Record Back 65 Million Years

Caelestiventus hanseni 
Britt, Dalla Vecchia, Chure, Engelmann, Whiting & Scheetz, 2018

Illustration: Michael Skrepnick 

Pterosaurs are the oldest known powered flying vertebrates. Originating in the Late Triassic, they thrived to the end of the Cretaceous. Triassic pterosaurs are extraordinarily rare and all but one specimen come from marine deposits in the Alps. A new comparatively large (wing span >150 cm) pterosaur, Caelestiventus hanseni gen. et sp. nov., from Upper Triassic desert deposits of western North America preserves delicate structural and pneumatic details not previously known in early pterosaurs, and allows a reinterpretation of crushed Triassic specimens. It shows that the earliest pterosaurs were geographically widely distributed and ecologically diverse, even living in harsh desert environments. It is the only record of desert-dwelling non-pterodactyloid pterosaurs and predates all known desert pterosaurs by more than 65 Myr. A phylogenetic analysis shows it is closely allied with Dimorphodon macronyx from the Early Jurassic of Britain.

Fig. 4: Reconstructions of Caelestiventus hanseni  and Dimorphodon macronyx.
a, Schematic silhouette of a dimorphodontid pterosaur in dorsal view. b, Preserved skull and mandible elements of Chanseni. The left maxillojugal is completed with the premaxillary process from the right maxilla. The right mandibular ramus is mirrored and is completed with the rostral end from the left ramus. Missing teeth have been reconstructed. The right nasal and frontoparietal are mirrored. c, Skull and mandible of the largest D. macronyx reconstructed (from Sangster, 2003) and modified incorporating our observations.

 Scale bars: 0.5 m in a and 10 mm in b and c. 
a, angular; aof, antorbital fenestra; d, dentary; fr, frontal; j, jugal; l, lacrimal; mx, maxilla; mdf, medially deflected flange; n, nasal; nvf, neurovascular foramen; pa, parital; pmx, premaxilla; sa, surangular; utf, upper temporal fenestra; vf, ventral flange.

Systematic palaeontology. 
Pterosauria Kaup, 1834 
Dimorphodontidae Seeley, 1870 

Caelestiventus hanseni gen. et sp. nov. 

Etymology. Caelestiventus hanseni comes from the Latin language: caelestis, ‘heavenly or divine’, and ventus, ‘wind’, referring to the volant nature of pterosaurs, and ‘hanseni’, honouring Robin L. Hansen, Bureau of Land Management (BLM) geologist, who facilitated work at the Saints & Sinners Quarry


Illustration: Michael Skrepnick 

Caelestiventus hanseni is the first record of a desert-dwelling, non-pterodactyloid pterosaur, predating by >65Ma all known desert occurrences of pterosaurs. It shows that in the Late Triassic—early in their evolution and diversification—pterosaurs were widely distributed and lived in a broad range of habitats, including inland deserts far (>800 km) from the sea. Despite their morphological similarity, C. hanseni and D. macronyx lived in very different environments. Dimorphodon was an island dweller45 in a humid climate46 and was preserved in the marine Blue Lias (Hettangian–Sinemurian) of southern England (Sangster, 2003). C. hanseni indicates that dimorphodontids originated by the Late Triassic and survived the end-Triassic extinction event

Brooks B. Britt, Fabio M. Dalla Vecchia, Daniel J. Chure, George F. Engelmann, Michael F. Whiting and Rodney D. Scheetz. 2018.  Caelestiventus hanseni gen. et sp. nov. Extends the Desert-dwelling Pterosaur Record Back 65 Million Years. Nature Ecology & Evolution.  DOI: 10.1038/s41559-018-0627-y

Rare triassic pterosaur discovered by BYU paleontologists  news.byu.edu/node/11801 via @@BYU
Utah Pterosaur Was Desert-Dwelling Badass...Pelican? - Dead Things  blogs.discovermagazine.com/deadthings/2018/08/13/utah-pterosaur/

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