Babies are born with about 300 to 350 bones, but many of these fuse together between birth and maturity to produce an average adult total of 206. Bone counts vary according to the method used to count them, because a structure may be treated as either multiple bones or as a single bone with multiple parts.
Male (A) and female (B) pelves are easily distinguishable by their shape. (From Oaties, Carol A. Kinesiology—The Mechanics and Pathomechanics of Human Movement. Baltimore: Lippincott, Williams & Wilkins, 2004.)