Conspecificity of two pocket mice, Perognathus goldmani and P. artus

The authors reassess two named taxa of pocket mice from parts of Sonora, Sinaloa, Chihuahua and Durango, arguing they are conspecific. They compare external coloration, skull dimensions (occipitonasal length, mastoidal breadth, interparietal width), hind-foot and tail measurements, and tympanic bulla inflation across specimens collected along geographic transects, documenting intermediate forms and clinal variation. Overlapping variation and geographic intermediacy lead to treating artus as a subspecies of goldmani. The study presents occurrence records, maps, measurement summaries, and notes on pelage darkening correlated with local substrate.