Os clitoridis

The os clitoridis (also called the os clitoris, clitoral bone or baubellum; pl.: baubella) is a bone inside the clitoris of many placental mammals. It is absent from the human clitoris, but present in the clitoris of some primates, such as ring-tailed lemurs and non-human great apes. However, in the latter case, the bone is greatly reduced in size.^[1]^[2]^[3] It is homologous to the baculum in male mammals.

The structure is more evolutionarily labile than the baculum, exhibiting both more inherent variability and more gains and losses over time,^[4] which has been interpreted as evidence for its non-functionality.^[4]

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, especially given the high level of variation within species as well as between them.^[5]

^ "A Long-Lost Bone". National Geographic Society. 3 September 2013. Archived from the original on March 3, 2021.
^ Martin, Robert D. (2007). "The evolution of human reproduction: A primatological perspective". American Journal of Physical Anthropology. 134: 59–84. doi:10.1002/ajpa.20734. PMID 18046752. S2CID 44416632.
^ Friderun Ankel-Simons (27 July 2010). Primate Anatomy: An Introduction. Elsevier. ISBN 978-0-08-046911-9.
^ ^a ^b Lough-Stevens, Michael; et al. (January 2018). "The baubellum is more developmentally and evolutionarily labile than the baculum". Ecology and Evolution. 8 (2): 1073–1083. doi:10.1002/ece3.3634. PMC 5773289. PMID 29375780.
^ Sloan, Nadia (September 2019). "The evolution of female genitalia". Journal of Evolutionary Biology. 32 (9): 882–899. doi:10.1111/jeb.13503. PMID 31267594.

[1] "A Long-Lost Bone". National Geographic Society. 3 September 2013. Archived from the original on March 3, 2021.

[2] Martin, Robert D. (2007). "The evolution of human reproduction: A primatological perspective". American Journal of Physical Anthropology. 134: 59–84. doi:10.1002/ajpa.20734. PMID 18046752. S2CID 44416632.

[Ankel-Simons2010-3] Friderun Ankel-Simons (27 July 2010). Primate Anatomy: An Introduction. Elsevier. ISBN 978-0-08-046911-9.

[Lough-4] Lough-Stevens, Michael; et al. (January 2018). "The baubellum is more developmentally and evolutionarily labile than the baculum". Ecology and Evolution. 8 (2): 1073–1083. doi:10.1002/ece3.3634. PMC 5773289. PMID 29375780.

[5] Sloan, Nadia (September 2019). "The evolution of female genitalia". Journal of Evolutionary Biology. 32 (9): 882–899. doi:10.1111/jeb.13503. PMID 31267594.

[1]

[2]

[3]

[4]

[5]