Gwawinapterus

• British Columbia, Canada ( Northumberland Formation)

• Gwawinapterus Beardi Arbour & Currie, 2010

Gwawinapterus ( " winged Raven" ) is a fossil genus from the Upper Cretaceous of Canada, based on a jaw fragment including teeth. The only way is Gwawinapterus Beardi. The genus was erected in 2010 and assigned to the Istiodactylidae, a group of pterosaurs, possibly as scavengers a similar ecological niche occupied as today's vultures. This would Gwawinapterus both the first from the Upper Cretaceous known Istiodactylidae and the first from the Upper Cretaceous pterosaur known tooth-bearing. However, a 2012 published study came to the conclusion that the fossil was not part of a pterosaur, but at a bone of fish from the group of Saurodontidae.

The name derives from Gwawinapterus Gwa'wina ( " Raven" ) from the language Kwak'wala ago, as well as Pteron ( " wing"), from Ancient Greek. Kwak'wala is spoken by the Kwakwaka'wakw, an Indian tribe of northern Vancouver Island. The second part of the species name, Beardi honors Graham Beard, the discoverer of the fossil.

Characteristics and classification

The only fossil is obtained within a calcite concretion, showing a portion of a jawbone. The fossil was revealed after the concretion was mechanically split into two halves. On one half there is a large part of the bone material, which is, however, splintered by the cleavage in many places, while found on the back plate, the corresponding footprints and other bones. The jaw bone is poor, the teeth but well preserved.

In the first description by Victoria Arbour and Philip Currie Gwawinapterus is attributed to the pterosaur family Istiodactylidae. On one belonging to this group have common characteristics of dental crowns: These are triangular, laterally ( labiolingual ) flattened and straight; a sawing action ( serration ) does not exist. In the spring of 2012 reported pterosaur specialist Mark Witton doubt as to the membership of the pterodactyls to: The change of teeth in all pterodactyls proceeds by the replacement tooth erupts behind the tooth to be replaced - the Gwawinapterus Fossil show, however, that the replacement teeth directly below the teeth to be replaced sit. Researchers led by Romain Vullo finally argue in autumn 2012 that the dental features described are typical not only for Istiodactyliden, but also for saurodontide fish like Saurodon and Saurocephalus. The jaw fragment shows at least 25 tightly-packed teeth; This configuration is typical of saurodontide fish, but not for Istiodactyliden that showed mostly less than 15 teeth per jaw half, which was less densely packed. Vullo and colleagues interpreted the fossil as an incomplete isolated maxilla. The leading edge of the fossil would represent the suture, which separates the maxilla from the premaxilla missing.

Vullo and colleagues ( 2012) could not detect any unique qualities enabling the fossil of known Saurodontiden genera could delimit. Consequently, they declared the genus Gwawinapterus as a noun dubium ( dubious name).

Fund and paleoenvironment

The fossil comes from the island Hornby Iceland, which ( Canada British Columbia ) is preceded by Vancouver Iceland. It was collected in the north- west of the island ( Collishaw Point). Collishaw Point is a rich reference for fossiliferous Calcitkonkretionen, are known finds of numerous plants, invertebrates, bony fish, sharks and mosasaurs. 2005 also the discovery of birds from the groups Ornithurae and Enantiornithes was announced. Geologically, at the locality of the Northumberland Formation, which mainly built up of dark gray silty pelites and coarser turbidite deposits that were deposited in deeper water. Saurodontide fish like Prosaurodon, Saurocephalus and Saurodon are widespread in the Upper Cretaceous of North America.