noun, plural: baculums or bacula
A baculum is a bone located in the glans penis or glans clitoridis of many mammals (e.g. certain primates, Rodentia species, Lagomorpha species, Eulipotyphla species, and Carnivora species). The baculum may be of variable size and shape; the size and shape are often a characteristic of a species. It is particularly developed in carnivores. It may reach a length of more than 10 cm. Marmosets that weigh around 500 g typically have a baculum of 2 mm in length. A 4.5 feet-long baculum was recovered from an extinct species of walrus.
Most placental mammals have baculum that aids them by providing and keeping sufficient stiffness during copulation. It allows the male to mate with a female for a long time. A homologue occurs in certain female mammals, i.e. baubellum or os clitoridis, which is a bone in the clitoris.
Humans, ungulates, elephants, monotremes, marsupials, lagomorphs, hyenas, sirenians, dolphins, porpoises, and whales are some of the mammals that do not have baculum in penis. Erection of penis is attained through blood pressure in the corpora cavernosa.
Word origin: Latin baculum (“stick, staff, sceptre, cudgel”)
- penile bone
- penis bone
- os penis