baculum [bak′yo͞o ləm]n.pl. bacula [bak′yo͞olə] or baculums 〚L, a stick: see BACILLUS〛a slim bone that supports rigidity of the penis in many mammals, including rodents, carnivores, and primates
* * *▪ anatomyalso called Os Penis, or Os Priapithe penis bone of certain mammals. The baculum is one of several heterotropic skeletal elements—i.e., bones dissociated from the rest of the body skeleton. It is found in all insectivores (e.g., shrews, hedgehogs), bats, rodents, and carnivores and in all primates except humans. Such wide distribution suggests that it appeared early in mammalian evolution.
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