Arthropterygius


Arthropterygius is an extinct genus of ophthalmosaurid ichthyosaur which existed in Canada, Spitsbergen, Russia and possibly Norway during the late Jurassic period.

Classification

It contains the type species Arthropterygius chrisorum, named in 2010 by Erin E. Maxwell. Arthropterygius is the generic replacement name for Ophthalmosaurus chrisorum, named in 1993 from fossils found on Melville Island in the Northwest Territories. Its fossils are the most complete of any ichthyosaur in the Canadian Arctic. A. chrisorum has several features that separate it from the genus Ophthalmosaurus, including a highly angled articulation between the radius and ulna and the humerus and a foramen for the internal carotid artery on the posterior surface of the basisphenoid. Maxwell 2010 found it to be the sister taxon of Caypullisaurus, an ophthalmosaurid from Argentina. However, many recent cladistic analyses found it to be the basalmost member of the Ophthalmosauridae.
Zverkov and Prilepskaya synonymize Janusaurus, Palvennia, and Keilhauia with Arthropterygius.
The following cladogram shows a possible phylogenetic position of Arthropterygius in Ophthalmosauridae according to an analysis done by Zverkov and Prilepskaya in 2019.