Lesser trochanter
The lesser trochanter of the femur is a conical eminence, which varies in size in different species. Paleontology. The position of the lesser trochanter close to the head of the femur is one of the defining characteristics of the Prozostrodontia, which is the clade of cynodonts including mammals and their closest non-mammaliform relatives. It was erected as a node-based taxon as the least inclusive clade containing "Prozostrodon brasiliensis", "Tritylodon langaevus", "Pachygenelus monus", and "Mus musculus" (the house mouse). All living mammals have a lesser trochanter, whose size, shape, and position is distinctive to their species. Structure . In humans the lesser trochanter varies in each individual, within narrow limits. It projects from the lower and back part of the base of the femur neck. From its apex three well-marked borders extend: The summit of the lesser trochanter is rough, and gives insertion to the tendon of the psoas major muscle and the iliacus muscle. Clinical significance. The lesser trochanter can be involved in an avulsion fracture.