An Analysis of Hair Structure and Its Phylogenetic Implications among Heteromyid Rodents

Hair morphology of 36 species of the family Heteromyidae including the genera Dipodomys, Perognathus, Microdipodops, Liomys, and Heteromys was studied using both light and scanning electron microscopy. Variables investigated included length and width of hair, imbricate scale pattern, external and cross-section form of hair, and medullary characteristics. Although the hair of individual species could be characterized with detailed study, we do not believe that hair structure will be of value in evolutionary studies of this group below the generic level. The overhair of heteromyid rodents falls into two morphological types-hair which is round to oval in outline and hair which has a trough along the dorsal surface. Hair of the first type is found in most perognathines, and all members of the genera Dipodomys and Microdipodops. Troughed hairs are found in all chaetodipines, Liomys, and Heteromys and the perognathines, P. ampulus and P. formosus