The massive body proportions, and the very fine, dense cephalic surface sculpture, are hallmarks of Pogonomyrmex wheeleri - North America's largest Pogo. [scroll down for additional notes/references]
Pogonomyrmex wheeleri is the largest Pogo species in North America, with an average worker size of 9.5mm to 11.5mm.
The range of this ant is limited to Sinaloa, and Narayit, in Mexico.
·Cole, A.C. 1968. Pogonomyrmex Harvester Ants: A Study of the Genus in North America. Knoxville, University of Tennessee Press
·Taber, S.W. 1998. The World of the Harvester Ants. College Station, TX, Texas A&M University Press