Scientists have long thought that a lizard losing a leg should be a death sentence. New evidence seems to overturn this assumption, showing that some lizards can not only survive, but even thrive after losing one or more limbs.

James Stroud, an evolutionary biologist at the Georgia Institute of Technology, has spent years catching lizards in the wild to study how they evolve. He and his colleagues long thought that even the smallest difference in the length of a lizard’s leg could affect its ability to run from predators and chase their prey. Losing an entire limb seemed much more severe.

However, every now and then he and his colleagues would observe something odd. “We’ll find a lizard completely missing its leg, and it seems fine,” Dr. Stroud said. He casually calls them “three-legged pirate lizards.”