Based on packrat (Neotoma spp.) midden fossil assemblages,
the author was able to reconstruct distributional shifts for a
number of species that formerly lived in the Chihuahuan Desert
regions of New Mexico, Texas and the Mexican state of Coahuila
(Elias, 1992). That study revealed that the various species extirpated
from the Chihuahan Desert have shifted their distributions
in almost every possible direction in response to changing
environments.