title: Qualitative cranial characters distinguishing Sigmodon hispidus and Sigmodon arizonae and the distribution of these two species in northern Mexico.
mesh_terms: D000818:Animals; D001130:Arizona; D002508:Cephalometry; D008800:Mexico; D051381:Rats / Q000033:anatomy & histology / Q000145:classification*; D012886:Skull / Q000033:anatomy & histology*