Acta Zoologica Cracoviensia, 13() 1968
Mandibular Musculature and the Origin of the Subfamily Arvicolinae (Rodentia)
Abstract:
As the fossil record of the arvicoline rodents becomes better known, it has become increasingly difficult to separate primitive genera from similar cricetine rodents on the basis of dental morphology. In search of criteria other than tooth pattern, an examination of the mandilabular musculature and its expresion in bone structure was made. Several characters of the mandible were found to be more or less typical of the arvicoline and not of the cricetine rodents. Examination of these characters in middle and late Pliocene arvicoline and cricetine rodents of both the Old and New World quite clearly defined the genus Promimomys as being arvicoline and the genera Baranomys and Microtodon as cricetine even though dental patterns are conspicuously similar. A fourth genus, Microtoscoptes from the middle Pliocene of both Old and New Worlds, is retained in the subfamilly Arvicolinae, although both dental and mandibular morphology strongly suggest that it represents a separate lineage of cricetine rodents closely paralleling the arvicolines in some respects but differing in others.
