Nurhachius

Nurhachius was a genus of istiodactylid pterodactyloid pterosaur from the Barremian-Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China.

Description
The genus was named in 2005 by Wang Xiaolin, Alexander Kellner, Zhou Zhonge and Diogenes de Almeida Campos. The type species is Nurhachius ignaciobritoi. The genus name refers to Nurhaci, the first khan of the Qing Dynasty, whose original power base encompassed the region where the fossil was found. The specific name honours the late Brazilian paleontologist Ignácio Aureliano Machado Brito, who pioneered the study of pterosaurs in his country.

The genus is based on holotype IVPP V-13288, a partial skull and skeleton. The skull is elongated with a preserved length of 315 millimetres and an estimated total length of about 330 millimetres. The nasoantorbital fenestra, the large skull opening, is relatively long at 58% of the skull length. The lower jaws have a length of 291 millimetres. The skull is similar to that of Istiodactylus, which lived at about the same time in what is now England, especially in the teeth that are compressed side to side and the long fenestra. However, it differs from Istiodactylus in several details, including a significantly lower skull, different jugal and a slight curve to the upper margin of the lower jaw. The teeth are curved to the back, have three roots and are robust. They are limited to the anterior ends of the jaws; there are 28 teeth in the upper jaws and 26 in the lower jaws for a total of 54. Most elements of the postcranial skeleton are known, with the exception of some cervical vertebrae, the ribs, the tail and the two most extreme phalanges of the wing finger. Its wingspan was estimated at 2.4-2.5 m (7.87-8.20 ft).[1]

The describers pointed out several similarities with the Pteranodontoidea (here used in the sense of the clade Pteranodon + Istiodactylus + Anhangueridae) and one, the warped deltopectoral crest of the humerus, unique to just the clade Istiodactylus + Anhangueridae. A cladistic analysis by Wang showed Nurhachius to be a member of the Istiodactylidae within the much larger Dsungaripteroidea sensu Kellner.

Its position as being closely related to Istiodactylus was supported by the analysis in a publication by Lü Junchang.[2] In 2008 Lü suggested Nurhachius was a subjective junior synonym of Liaoxipterus.