No reconstruction of the fragmentary partial skull was offered.

It consists of a partial skeleton with a fragmentary skull.

It is known from a single fragmentary skull that was found in the Maastrichtian-age Hell Creek Formation.

A second species, C. gracile, was named by Oppel in 1862 based on a fragmentary skull.

Harrison (1953) found that dental wax and Sellotape were useful in provisional reconstructions of very fragmentary skulls.

Leaellynasaura is known from several specimens including two nearly complete skeletons and two fragmentary skulls.

The holotype is MN 6592-V, a fragmentary skull with a more rounded crest.

It is known from a single fragmentary skull and associated postcranial bones representing the species Yikezhaogia megafenestrala.

A more fragmentary skull was also recovered, associated with some ribs, fragmentary vertebrae, and a complete forelimb.

Macrodelphinus is known from a fragmentary skull from southern California.