Arthropterygius

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

Arthropterygius Temporal range: Late Jurassic
Cranial elements of A. chrisorum
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	†Ichthyosauria
Family:	†Ophthalmosauridae
Genus:	†Arthropterygius Maxwell, 2010
Type species
†Arthropterygius chrisorum (Russel, 1993 [originally Ophthalmosaurus])
Other species
†A. kui? (Delsett et al., 2017)[1] †A. hoybergeti? (Druckenmiller et al., 2012) †A. lundi? (Roberts et al., 2014) †A. volgensis (Kasansky, 1903)

Classification

Cranial elements of A. volgensis

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 (a major artery that supplies blood to the brain) on the posterior surface of the basisphenoid. Maxwell 2010 found it to be the sister taxon of Caypullisaurus, an ophthalmosaurid from Argentina.[2] However, many recent cladistic analyses found it to be the basalmost member of the Ophthalmosauridae.[3][4]

Zverkov and Prilepskaya (2019) synonymize Janusaurus, Palvennia, and Keilhauia with Arthropterygius.[5]

The following cladogram shows a possible phylogenetic position of Arthropterygius in Ophthalmosauridae according to an analysis done by Zverkov and Prilepskaya in 2019.[5]

Size comparison

Ophthalmosauridae

Nannopterygius enthekiodon     Gengasaurus nicosiai     Paraophthalmosaurus saveljeviensis         Ophthalmosaurinae   Acamptonectes densus       Ophthalmosaurus icenicus       Mollesaurus periallus     Ophthalmosaurus natans         Arthropterygius   A. lundi     A. volgensis       A. chrisorum (PMO 222.669)     A. chrisorum         Platypterygiinae   Sveltonectes insolitus       Aegirosaurus leptospondylus         Caypullisaurus bonapartei     Leninia stellans           Grendelius mordax     Grendelius alekseevi           Undorosaurus gorodischensis     Undorosaurus nessovi         Plutoniosaurus bedengensis     Maiaspondylus lindoei       Sisteronia seeleyi     Platypterygius hercynicus         Platypterygius americanus     Platypterygius australis

See also

• List of ichthyosaurs
• Timeline of ichthyosaur research

References

1. Lene Liebe Delsett; Aubrey J. Roberts; Patrick S. Druckenmiller; Jørn H. Hurum (2017). "A New Ophthalmosaurid (Ichthyosauria) from Svalbard, Norway, and Evolution of the Ichthyopterygian Pelvic Girdle". PLoS ONE. 12 (1): e0169971. Bibcode:2017PLoSO..1269971D. doi:10.1371/journal.pone.0169971. PMC 5266267. PMID 28121995.
2. Maxwell, E.E. (2010). "Generic reassignment of an ichthyosaur from the Queen Elizabeth Islands, Northwest Territories, Canada". Journal of Vertebrate Paleontology. 30 (2): 403–415. doi:10.1080/02724631003617944.
3. Fischer, Valentin; Edwige Masure; Maxim S. Arkhangelsky; Pascal Godefroit (2011). "A new Barremian (Early Cretaceous) ichthyosaur from western Russia". Journal of Vertebrate Paleontology. 31 (5): 1010–1025. doi:10.1080/02724634.2011.595464.
4. Valentin Fischer; Michael W. Maisch; Darren Naish; Ralf Kosma; Jeff Liston; Ulrich Joger; Fritz J. Krüger; Judith Pardo Pérez; Jessica Tainsh; Robert M. Appleby (2012). "New Ophthalmosaurid Ichthyosaurs from the European Lower Cretaceous Demonstrate Extensive Ichthyosaur Survival across the Jurassic–Cretaceous Boundary". PLoS ONE. 7 (1): e29234. Bibcode:2012PLoSO...729234F. doi:10.1371/journal.pone.0029234. PMC 3250416. PMID 22235274.
5. Zverkov, Nikolay G.; Prilepskaya, Natalya E. (2019). "A prevalence of Arthropterygius (Ichthyosauria: Ophthalmosauridae) in the Late Jurassic—earliest Cretaceous of the Boreal Realm". PeerJ. 7: e6799. doi:10.7717/peerj.6799. PMC 6497043. PMID 31106052.