The braincase, the portion of the bony skull that surrounds the brain, long has been considered a rich source of data by vertebrate morphologists interested in testing hypotheses of evolutionary relationships and studying the complex relationship between the skeletal and nervous systems. The number of taxa for which detailed descriptions of braincase anatomy are available, however, does not come close to accurately reflecting the taxonomic diversity within most vertebrate groups. One reason for this disparity is that the study of internal cranial anatomy largely is a destructive process and therefore logistically difficult for rare taxa that are not well represented in museum collections.

We utilized X-ray computed tomography as a non-destructive technique for visualizing and describing the braincase of the rare anguimorph lizard, Shinisaurus crocodilurus, which today is known to inhabit only portions of southeastern China and northeastern Vietnam. In addition to revealing internal details of the braincase elements, computed tomography allowed us to provide the first description of the cranial osteoderms (bones that lie within the skin around the head) and inner ear cavities of this enigmatic lizard. Our examination of both juvenile and adult specimens of S. crocodilurus emphasizes the need for increased understanding of both individual and ontogenetic variation in anguimorph cranial osteology.