Keilhauia nui was named by Delsett et al. (2017) [An ophthalmosaurid with the following autapomorphies: ilium anteroposteriorly expanded at the dorsal end; ischiopubis shorter or subequal in length to the femur (differs from all other Middle-Late Jurassic and Cretaceous ophthalmosaurids, but found in some specimens of Stenopterygius sp). The species also possesses the following unique character combination: Posterior dorsal and anterior caudal centra less than 3.5 times as high as long (4 times or more in Ophthalmosaurus icenicus and Arthropterygius chrisorum); glenoid contribution of the scapula larger than coracoid facet (smaller in Caypullisaurus bonapartei and Sveltonectes insolitus); small acromion process of scapula (prominent in Brachypterygius extremus, Acamptonectes densus, Platypterygius americanus, Caypullisaurus bonapartei and Sveltonectes insolitus); anteromedial process of coracoid present (not present in Caypullisaurus bonapartei and Platypterygius australis)[26, 54]; absence of a strongly developed deltopectoral crest of the humerus (present in Caypullisaurus bonapartei, Platypterygius americanus and Sveltonectes insolitus); humerus with facet for preaxial accessory element anterior to radius (absent in Brachypterygius extremus, Maiaspondylus lindoei, Aegirosaurus leptospondylus and Sveltonectes insolitus); posteriorly deflected ulnar facet (absent in Brachypterygius extremus, Maiaspondylus lindoei, Caypullisaurus bonapartei, Platypterygius australis, Aegirosaurus leptospondylus, Sveltonectes insolitus and Cryopterygius kristiansenae); lack of a contact between the humerus and intermedium (present in Brachypterygius extremus, Maiaspondylus lindoei and Aegirosaurus leptospondylus); complete fusion of the ischium and pubis lacking an obturator foramen (only proximal fusion in Cryopterygius kristiansenae and Undorosaurus gorodischensis, present with foramen in Ophthalmosaurus icenicus); medial margin of ischiopubis straight in dorsal and ventral view (shared with Janusaurus lundi only)[29]; femur with two distal facets (three in Platypterygius americanus, P. australis, P. hercynicus and Paraophthalmosaurus saratoviensis).]. Its type specimen is PMO 222.655, a partial skeleton (articulated, partial skeleton consisting of an incomplete rostrum, the dorsal and preflexural vertebrae, the right pectoral girdle and forefin, most of the pelv), and it is a 3D body fossil. Its type locality is Keilhauia-type locality, which is in a Berriasian marine shale/carbonate in the Agardhfjellet Formation of Svalbard and Jan Mayen.