part of part of in taxon has muscle origin has muscle origin has muscle insertion has muscle insertion Amniota Mammalia tibia ilium hindlimb hindlimb muscle ambiens muscle ambiens The tendon of the ambiens muscle passes obliquely over the knee joint. It assists in the control of the bird's toes. This muscle is present in some reptiles but not mammals. It is present in caiques and some other South American genera, but missing in most parrot genera. This was first noted by Garrod (1874) who proposed using this and other anatomical differences to classify parrots. For oproperty_value external_definitionanatomical differences among parrots see carotid arteries, furcula, and uropygial gland UBERON:0013511 A long muscle found in reptiles that originates on the ilium and crosses the acetabulum and the knee joint before being inserted on the tibia.