Genus: Callawayasaurus CARPENTER, 1999
Etymology: In honor of Jack Callaway, who in his briefe career as a vertebrate paleontologis, did much to improve our understanding of marine reptiles.

Species: columbiensis (WELLES, 1962) CARPENTER, 1999
Etymology:
= Alzadasaurus columbiensis WELLES, 1962

Holotype: UCMP 38349

Locality: Loma de la Catalina, 6 km west of Leiva, About 300 meters north of road from Leiva to Chiquinquira, Boyaca Province, Colombia.

Horizon: Paja Formation.

Biostratigraphy:

Age: Upper Aptian Stage, Middle Gallic Subepoch, Uppermost Early Cretaceous Epoch, Early Cretaceous.

Material: Skull and fine skeleton lacking only distal parts of paddles, ischia, ilia and tail.

Note: Pathological cervicl vertebrae, and a series of pathological vertebral series (Sassoon, 2019).