Callosity

A callosity is another name for callus, a piece of skin that has become thickened as a result of repeated contact and friction. A callosity is another name for callus, a piece of skin that has become thickened as a result of repeated contact and friction. When occurring on an animal's buttocks, as with baboons, they are specifically called ischial callosities. Ischial relates to the ischium: it forms the lower and back part of the hip bone.