Specialized Cranial and Dental Anatomy of Rodents

Abstract

Rodents can be separated from all other eutherian mammals on the basis of a number of characteristics. Because the focus of this book is fossil rodents, the characters cited here are only those that are commonly preserved in fossils, that is, the skeleton and dentition. The skull bones and cranial foramina of rodents that are discussed throughout this work are diagrammed in Fig. 2.1. In the systematic chapters, reference to size of rodents as small, medium, and large is defined as follows: small, similar in size to modern field mice (Peromyscus) or chipmunk (Tamias) or smaller; medium, no larger than a Recent tree squirrel (Sciurus) or muskrat (Ondatra); and large, the largest rodents near the size of modern beaver (Castor) or larger.