Normal pelvic dimorphism is the result of the male pelvis acquiring morphological features during postnatal development that differ from those of the female. The first dimorphic features appear at 32 days of age. At 76 days of age the male pelvis has eleven dimorphic features that constitute the dimorphism of the normal adult. The development of five of the 11 features is dependent on the presence of the testes, whereas, the other six develop independently of the testes. The testes-dependent features develop in males castrated at birth and treated with testosterone. The postnatal development of the female-type pelvis in the normal female is not dependent on the presence of the ovaries.