Intersexual and intrasexual interactions by female spotted hyenas, (Crocuta crocuta), are correlated with the ability of the heavier and more aggressive females to dominate males at large carcasses, the principal food of spotted hyenas. Female spotted hyenas have a modified clitoris closely resembling a penis. A slightly bilobed scrotum containing fat and connective tissue contributes to the male-like appearance of the female sexual facies. Penile and pseudopenis erection by spotted hyenas occurs primarily during social encounters at carcasses and elsewhere. Analyses here, based on interspecies comparisons of spotted hyena, brown hyena (Hyaena brunnea) and striped hyena (H. hyaena) morphology, behavior and ecology and interpopulation comparisons of spotted hyenas suggest possible gradualistic evolutionary interpretations of the pseudopenis.