Unlike snakes, these lizards spend most of their lives underground in an area about the size of a small table.
Snakes are legless lizards, too, but these four species are not snakes. They have movable eyelids, so they can blink; they don't shed their skin in a single piece; some have external ear openings; and they don't "coil" or "slither" much. They are also said to be "more rigid" than snakes.
These four types are small, usually not longer than 8 inches and about as thick around as a pencil.
To find the species, researchers put thousands of pieces of cardboard at various sites in the hopes some of the lizards would make an unlikely above-ground appearance. They are sometimes found above ground, but only under logs or dead wood, where the ground is cool and damp.
The four species are silver-bellied Anniella alexanderae, yellow-bellied Anniella campi, purple-bellied Anniella grinnelli, and Anniella stebbinsi, all named after UC Berkeley scientists.