Generic reassignment of an ichthyosaur from the Queen Elizabeth Islands, Northwest Territories, Canada

Simbirskiasaurus and Pervushovisaurus reassessed: implications for the taxonomy and cranial osteology of Cretaceous platypterygiine ichthyosaurs

“…The basioccipital has no extracondylar area and lacks a peripheral groove, as is also the case in Arthropterygius chrisorum (see Maxwell, 2010;Fernández & Maxwell, 2012), platypterygiine ophthalmosaurids , and possibly Palvennia hoybergeti Druckenmiller et al, 2012 (for which a single poorly preserved basioccipital is known). Among platypterygiines, the basioccipital of Simbirskiasaurus birjukoυi is very similar to that of both some Platypterygius specimens (e.g.…”

“…We therefore ran a second analysis where all taxa with more than 50% of data missing were excluded, with the exception of Simbirskiasaurus birjukovi and Pervushovisaurus bannovkensis. The following taxa were therefore excluded in the second analysis: Stenopterygius cayi (Fernández, 1994), Arthropterygius chrisorum (Russell, 1993), Mollesaurus periallus Fernández, 1999, Maiaspondylus lindoei Maxwell & Caldwell, 2006b, Athabascasaurus bitumineus Maxwell, 2010, andLeninia stellans Fischer et al, 2014a. The resulting matrix contains 52 characters and 14 taxa.…”

A basal thunnosaurian from Iraq reveals disparate phylogenetic origins for Cretaceous ichthyosaurs

“…Ophthalmosauridae appear in the fossil record during the Aalenian (Middle Jurassic; [9]) and persist long after other lineages disappeared; it is the only clade considered to have Cretaceous representatives. Cretaceous taxa are traditionally considered to be low in diversity and disparity [10,11] and to represent the descendants of a Late Jurassic ancestor [12][13][14]. Both ideas have contributed to the popular hypothesis that Cretaceous ichthyosaurs represent the last remnants of a group that was in decline ever since the Middle or Late Jurassic [10,11], a view challenged only recently [15,16].…”

Morphology and orientation of the ichthyosaurian femur

“…The humerus has only two distal facets for radius and ulna. Most of the ophthalmosaurids have three distal facets: Ophthalmosaurus icenicus (Kirton 1983), Aegirosaurus leptospondylus (Bardet and Fernandez 2000), Caypullisaurus bonapartei (Fernandez 1997), Brachy pterygius extremus (Boulenger 1904), Undorosaurus goro dischensis (Efimov 1999), Janusaurus lundi (Roberts et al 2014), Acamptonectes densus (Fischer et al 2012), and Arthropterygius (Maxwell 2010). The ophthalmosaurids with only two distal facets are Cryopterygius kristiansenae (three distal facets on the right humerus; , Nannopterygius enthekiodon (Hulke 1871), Sveltonectes (Fischer et al 2011), and many species of Platypterygius (McGowan and Motani 2003).…”

“…The similar size and association of the bones in one sector of the quarry suggest that they belong to a single individual. Ophthalmosauridae are known from the Jurassic and Cretaceous, and include taxa such as Ophthalmosaurus (Kirton 1983), Aegirosaurus (Bardet and Fernandez 2000), Nannopterygius (Hulke 1871), Caypullisaurus (Fernandez 1997), Janusaurus (Roberts et al 2014), Cryopterygius , Platy pterygius (Maxwell and Kear 2010), Acamptonectes (Fischer et al 2012), Arthropterygius (Maxwell 2010), and Undorosaurus (Efimov 1999). Clearly, C. kielanae is a member of Ophthalmosauridae.…”