From partial skeletons, a proatlas, atlas, axis, a third to ninth cervical vertebrae, and at least 16 dorsal, two sacral, and 45 caudal vertebrae have been reconstructed. The vertebrae are weakly amphicoelous, meaning both sides of the centrum are concave. The dorsal shield is made of two columns of paravertebral osteoderms and two lateral columns of accessory osteoderms. At least 12 horizontal rows of these make up the shield. Citing vague distinctions, Jove and colleagues, attempted to reclassify the genus "Hyposaurus" based on diagnostic characteristics and sort of taxonomic troubles. Flattening of the mandibular symphysis, used previously to distinguish between species, is not confirmed and only can be used to distinguish between "Hyposaurus" and "Congosaurus". Currently, width height ratio of teeth in different positions are being used to distinguish between species. The little variation between the species "Hyposaurus wilsoni" and "Hyposaurus nopcsai", means one of the two is a nomen dubium (Latin: "doubtful name"), although fossil evidence does suggest two species. The paper focuses on the at least 5 species of "Hyposaurus" or "Congosaurus" known from the Paleocene of the Iullemmeden Basin of Western Africa (Mali, Niger, Nigeria). The authors suggest using skull characteristics instead of mandibular characteristics for taxonomic distinctions because skulls are usually better preserved. A paper by Hastings and colleagues described a new skull of a dyrosaurid crocodyliform, found in the Cerrejón Formation of northern Colombia. They used mandibular and cranial characteristics to map it onto a cladogram with "Hyposaurus" and other taxa. Analysis supports an African origin to Dyrosauridae, with dispersal and radiation in South America in the Late Cretaceous or very early Paleocene. This specimen of dyrosaurid is the smallest of the dyrosauridae family found to date, with "Hyposaurus rogersii" as contender for the next smallest. In 2016, Salih and colleagues reported the first "Hyposaurus" fossil found in the Campanian to Maastrichtian Shendi Formation of Sudan. It was identified as a "Hyposaurus" based on the flat shape of the mandible (lower jawbone) and the elliptical shape of the mandibular symphysis (median line ridge of mandible).