The os clitoridis (also called the os clitoris or baubellum) is a bone inside the

clitoris The clitoris ( or ) is a female sex organ present in mammals, ostriches and a limited number of other animals. In humans, the visible portion – the glans – is at the front junction of the labia minora (inner lips), above the ope ...

of many

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

ian taxa. It is absent from the human clitoris, but present in the clitoris of some primates, such as the

ring-tailed lemur The ring-tailed lemur (''Lemur catta'') is a large strepsirrhine primate and the most recognized lemur due to its long, black and white ringed tail. It belongs to Lemuridae, one of five lemur families, and is the only member of the ''Lemur'' g ...

s. It is homologous to the

baculum The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone found in the penis of many placental mammals. It is absent from the human penis, but present in the penises of some primates, such as the ...

in male mammals. The structure is more evolutionarily labile than the baculum, exhibiting both more inherent variability and more gains and losses over time, which has been interpreted as evidence for its non-functionality. Other work posits that the variation in the os clitoridis could be driven by intersexual conflict, lock-and-key genital evolution, and

cryptic female choice Cryptic female choice is a form of mate choice which occurs both in pre and post copulatory circumstances when females in certain species use physical or chemical mechanisms to control a male's success of fertilizing their ova or ovum; i.e. by sele ...

, especially given the high level of variation within species as well as between them.

References

{{Anatomy-stub Clitoris Mammal anatomy