Key to the Rodentia
           
 
 Fur brown and fleece-like with guard hairs colored much like underfur; tail dorsoventrally flattened and scaly, without hair; second digit on hind foot with double “grooming claw” (Fig. 28); paraoccipital process not greatly elongate (Fig. 29a); infraorbital foramen small (Fig. 27b); cheek teeth more or less parallel rows
   
 Fur dark smoky gray overlaid with long yellowish guard hairs; tail round, scaly, and sparsely haired; no grooming claw on hind foot; paraoccipital processes greatly elongated and curving slightly forward (Fig. 29b); infraorbital foramen large; cheek teeth convergent anteriorly and decreasing in size from front to back (Fig. 30)
 
           
Artiodactyla
 - 
Carnivora
 - 
Chiroptera
 - 
Didelphimorphia
 - 
Insectivora
 - 
Lagomorpha
 - 
Rodentia
 - 
Xenarthra
Scientific Names - Common Names