The specimen was found in the Wabiskaw Member of the Clearwater Formation, which dates to the earliest Albian stage of the Early Cretaceous epoch, about 112 million years ago.

The maxillae are long, and extend upwards and fork into two ascending processes flanking the external naris, the rear one being the taller of the two and potentially reaching the prefrontal, one of the paired bones that form the upper edge of the orbit (eye socket).

The parietals (rear pair of skull roof bones), which bound the inner edges of the supratemporal fenestrae, do not form a sagittal crest.

[1] The rear surfaces of the exoccipitals (a pair of braincase bones) are rugged, considered to provide a site where the occipital muscles anchored.

[1] The rear part of the lower jaw externally is formed by the surangular and angular, with the latter overlapping the former and constituting the majority of the posterior mandible's outer surface.

Sparse, fine enamel ridges extend vertically along the sides of the thin, cone-shaped tooth crowns, which are otherwise smooth.

[1] There are 42 vertebrae in front of the hips Athtabascasaurus, an unusually low number for ophthalmosaurs, with this series measuring 1.509 meters (4.95 ft) long in the holotype.

[6] Acamptonectes densus Mollesaurus periallus Ophthalmosaurus natans Ophthalmosaurus icenicus Gengasaurus nicosiai Nannopterygius yasykovi Nannopterygius enthekiodon Nannopterygius saveljeviensis Nannopterygius borealis Arthropterygius volgensis Arthropterygius lundi Arthropterygius thalassonotus Arthropterygius hoybergeti Arthropterygius chrisorum Brachypterygius extremus Aegirosaurus leptospondylus Muiscasaurus catheti Leninia stellans Sveltonectes insolitus Athabascasaurus bitumineus Platypterygius americanus Acuetzpalin carranzai Platypterygius sachicarum Caypullisaurus bonapartei Grendelius mordax Grendelius alekseevi Grendelius pseudoscythicus Grendelius zhuravlevi Undorosaurus kielanae Undorosaurus nessovi Undorosaurus gorodischensis Platypterygius australis Plutoniosaurus bedengensis Simbirskiasaurus birjukovi Platypterygius hercynicus Sisteronia seeleyi Platypterygius platydactylus Maiaspondylus lindoei