Cryopterygius kielanae was named by Tyborowski (2016) [Medium size ophthalmosaurid ichthyosaur (estimated 3.5–4 m of total body length; based on comparisons of pectoral girdle and forefin size in other more complete ophthalmosaurids; the humerus and scapula are similar in size to those of Janusaurus lundi, which is estimated to be a medium-sized species), and is smaller in length than type species. Absence of a deep and wide ventral groove on the quadrate articular condyle (quadrate articular condyle divided by a deep and wide groove in Ophthalmosaurus icenicus, Sveltonectes insolitus, Acamptonectes densus, and Platypterygius australis). Humerus with tall and prominent dorsal process located in the middle of the dorsal surface of the bone, rather than less prominent dorsal process located at the posterior margin of the dorsal surface of the bone in C. kristiansenae. Humerus with prominent deltopectoral crest, rather than very weakly developed deltopectoral crest in C. kristiansenae (relatively low dorsal process and deltopectoral crest in Ophthalmosaurus icenicus, Aegirosaurus leptospondylus, and Caypullisaurus bonapartei). Humerus with two distal facets (three distal facets in Ophthalmosaurus icenicus, Brachypterygius extremus, Caypullisaurus bonapartei, Undorosaurus gorodischensis, Aegirosaurus leptospondylus, Janusaurus lundi, and Acamptonectes densus humeri). Proximal and distal ends of the femur anteroposteriorly broader in C. kielanae than in C. kristiansenae (relatively narrower femur in Ophthalmosaurus icenicus and Janusaurus lundi).]. Its type specimen is GMUL 3579-81, a partial skeleton ( a fragment of the lower jaw, isolated teeth, fragments of pterygoid and quadrate, parts of the cervical, dorsal, and caudal vertebral column, most of the left ), and it is a 3D body fossil. Its type locality is Owadów‐Brzezinki quarry (Unit I), which is in a Tithonian open shallow subtidal limestone in the Kcynia Formation of Poland.