Sexual dimorphism of the phallus in spotted hyaena (Crocuta crocuta)

The weight of the skinned phallus and the diameter of its shaft and glans did not differ significantly in the two sexes of spotted hyaena, but phallus length was greater in males. The urethra of the penis was surrounded by corpus spongiosum, while the urogenital canal of the clitoris was suspended beneath the erectile bodies in loose connective tissue, an arrangement compatible with dilatation of the canal during copulation and parturition. The average width of the phallic meatus in juvenile females exceeded that in males of any age and, in adults, the clitoridal meatus was > 10 times the width of the penile meatus. A robust retractor muscle situated dorsal to the urogenital canal further distinguished the clitoris from the penis; this muscle may play an important role in facilitating copulation.