Blunt-snouted dolphin (Platalearostrum hoekmani, "Albert Hoekman's spoon-rostrum") is a prehistoric pilot whale known from a single specimen (NMR-9991-00005362), consisting of a partial rostrum, partial maxilla, partial premaxilla, and partial vomer.
The holotype of C. venezuelensis — OR-1677, a partial left premaxilla bone — was discovered in the locality of El Breal of Orocual, in the Mesa Formation, in the state of Monagas, Venezuela, the country of which derives their species name.
A cleft palate may form in humans (and other tetrapods) where the tissues that will become the premaxilla and the maxilla fail to join during development.
In bony fish, amphibians, and reptiles, both maxilla and premaxilla are relatively plate-like bones, forming only the sides of the upper jaw, and part of the face, with the premaxilla also forming the lower boundary of the nostrils.
Oxalaia is known from the holotype MN 6117-V, fused premaxillae of a very large individual and from the referred fragment MN 6119-V, an isolated and incomplete left maxilla, which were found on Cajual Island, Maranhão of northeastern Brazil.