A deep sulcus forms in the left flank below the costal margin, and the space between the arm and the chest wall-the "brachio-thoracic triangle"-on the left side is much more marked than on the right; and the left iliac crest usually projects upwards and backwards.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition."
Alexander Miles Alexis Thomson
The single median sulcus on the anterior face of each incisor is typical of the genus Cratogeomys.
"Pleistocene Pocket Gophers From San Josecito Cave, Nuevo Leon, Mexico"
Robert J. Russell