Complete DNA sequences obtained from the mitochondrial cytochrome-b gene were examined in 41 individuals representing 11 currently recognized species of Geomys. Similar tree topologies were obtained from parsimony, genetic distance, likelihood, and Bayesian methods of data analyses. Phylogenetic relationships indicated 4 major clades that are referred to as species groups (bursarius, breviceps, personatus, and pinetis). The results also suggest the existence of several cryptic species that warrant further investigation.
