Scientists Finally Found The Clitoris On Snakes – And There Are Two

Researchers found the first evidence of a two-part sex organ called hemiclitoris in the nine species of female snakes they examined

By Corryn Wetzel

Female snakes have not one, but two clitoris, according to research documenting the first formal evidence of the sex organ in snakes. This two-part clitoris, called the hemiclitoris, is present in at least nine species of snakes.

“A lot is known about the genitals of male snakes, but not so much – really nothing – about females,” says Megan Folwell at the University of Adelaide in Australia. Previous research was “all over the place as to whether the snake’s clitoris existed.” Wanting to settle the debate, Folwell and his colleagues began dissecting specimens of female snakes from the University of Michigan zoology collection.

Folwell says it didn’t take much research. “You peel the skin off and it’s there in front of you,” she says. They found hemiclitores in all nine species they examined, and all of them were located under the snake’s tail.

Dissections and micro-CT scans revealed a range of hemiclitoris sizes and structures between species. The cantil adder (Agkistrodon bilineatus), a pit viper native to Mexico, has the largest hemiclitoris of nine species, while an Australian species, Ingram’s brown snake (Pseudonaja ingrami), has the smallest. Other species they looked at included the common death adder (Acanthophis antarcticus), Guatemalan milk snake (Abnormal lampropeltis) and carpet python (Morelia spilota). Folwell says she suspects that most, if not all, female snake species have hemiclitores.

The team also found that, like the two-part hemipenes of male snakes and lizards, female hemiclitores are composed of sensitive nerves and erectile tissue. But unlike hemipenes, female hemilitores lack the spines and hooks that are believed to aid in mating.

The work “provides compelling evidence that [the clitoris] is there, and it’s big, and it’s complex,” says Richard Shine at Macquarie University in Australia who did not participate in the work. “This is a big step forward in our understanding of sexual anatomy in reptiles.”

When it comes to studying animal genitalia, “I think the female side of things gets a bit lost,” Folwell says. “But now there’s a brilliant community of scientists studying female genitalia, which is really exciting.”

Journal reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2022.1702

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