The Pendulous Pseudo-Penis
Female spider monkeys have such large, pendulous clitorises that early researchers thought all spider monkeys were male.
Female spider monkeys possess one of the most dramatic clitorises in the primate world — so large and pendulous that it was historically mistaken for a penis.
Early researchers examining spider monkey troops were confused: they couldn't find any females. Eventually they realized the "small males" they'd been observing were actually females with elongated, erectile clitorises.
The spider monkey clitoris: - Hangs pendulously from the body - Is erectile, capable of becoming engorged - Contains an interior urethra passage - Can be 6-8 cm long — proportionally enormous for their body size
But here's the really interesting part: spider monkey clitorises have a functional purpose beyond sex.
The urethra runs through the clitoris, and females use it for scent marking. They urinate in a way that distributes droplets across surfaces, leaving chemical messages for other monkeys.
This makes the spider monkey clitoris a dual-purpose organ: both a potential pleasure center and a sophisticated communication tool.
Why did this evolve? Spider monkeys live in fission-fusion societies where group composition constantly changes. Scent marking may help females: - Communicate reproductive status - Mark territory - Maintain social bonds across distance
The spider monkey demonstrates that genital anatomy can evolve for purposes far beyond reproduction.