ENAMEL ULTRASTRUCTURE OF INCISORS, PREMOLARS, AND MOLARS IN THOMOMYS-CRATOGEOMYS, AND GEOMYS (RODENTIA, GEOMYIDAE)

Enamel ultrastructure seems to be a fairly constant trait in the family Geomyidae (Rodentia). Transverse sections of Thomomys, Cratogeomys, and Geomys incisors reveal varying thickness of the inner uniserial versus the outer radial enamel layers between genera, which may reflect differing fossorial lifestyles. Premolars and molars, in contrast to incisors, have an inner layer of radial enamel and an outer layer of multiserial enamel, an arrangement that probably is related to propalinal mastication. At high magnification, enamel prisms appear hollow and may contain enamel tubules.