It’s not a snake. It’s not a worm. And as far as legless lizards go, the Mexican mole lizard is a strange one.
Hours after setting up a pitfall trap that is designed to catch any animal that walks over it, herpetologist Sara Ruane from Rutgers University-Newark was excited by what she saw: “It was shocking to see one in this trap, I couldn’t believe it was in there.”
She was surprised to see the Mexican mole lizard, also known as Bipes biporus, because their underground lifestyle means they don’t spend too much time on the surface.
This month, Ruane was out with University of California Berkeley graduate student Kaitlyn Kraybill-Voth, who took the video, setting traps for a general biodiversity survey as part of an Islands and Seas field course in San Juanico, Baja California Sur.
Bipes biporus is what is known as an amphisbaenian—a group of legless lizards that, surprisingly, are not snakes even if they bear a strong superficial resemblance. They are more closely related to other lizards with legs than snakes. (Read more about a blind legless lizard found in Cambodia.)
All but three of the approximately 200 amphisbaenian species are legless, and all three with tiny legs are Bipes species. They possess flat, digging front limbs that help them move through lose soil while they are underground. They use both their front limbs and undulating movements of their bodies to get around.
They are only about 9 inches long with a very light pink appearance due to their subterranean lifestyle, where they live in shallow root beds and eat insects.
The original field study of Bipes biporus in the 1980s notes that out of over 2,000 individuals collected, only three were found on the surface, which is why Ruane was excited to find two during their field expedition.
They are not actually rare, but their life out of sunlight makes them an exciting and surprising sight to people who want to see them. Still, this legless lizard is not completely beloved in Baja, where it is called ajolote by the locals.
Folklore surrounding these animals is dicey, at best. In kind terms, some are worried it will use its two front limbs to crawl up a certain orifice when one squats down to use the bathroom.
Although this story has no factual basis, Ruane says some locals did bring it up when she showed them the two Bipes biporus they found. “The rumor is out there,” she laughs. (Learn about the critically endangered axolotl, another curious animal in Mexico.)
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