teD, you've got callipygian slightly crossed with
steatopygia, which are quite different, as a matter of fat.

callipygian - of, pertaining to, or having well-shaped or finely developed buttocks

steatopygia - an abnormal accumulation of fat in and behind the hips and thighs, found (more markedly in women than in men) as a racial characteristic of certain peoples, esp. the Hottentots and Bushmen of South Africa.

p.s. - the Greek Callipygos is the name of a famous statue of Venus.