Incisor Enamel Microstructure in Blind Mole Rats: Adaptive and Phylogenetic Significance

Abstract

The microscopic structure of the enamel in incisors of blind mole rats was investigated with scanning electron microscopy. Enamel microstructure was found to reflect both higher level taxonomic affinity and function. Samples representing four chromosomal species of the Spalax ehrenbergi superspecies complex were compared on the basis of five measured traits and found to differ only in total enamel thickness; this feature covaried with soil hardness. From comparisons with other fossorial rodents (Rhizomyidae, Geomyidae, and Bathyergidae), it is apparent that thick outer enamel and low band inclination, as well as zonation of the outer enamel, are functionally related to burrowing.