Xantusidae (Night Lizards) of the United States
The night lizards are related to the geckos and like them have soft skin, a somewhat flattened body, and no moveable eyelids. But unlike the geckos the night lizards have small round scales on their backs, large rectangular scales on their bellies, and large shields on the head. Their toes end in a sharp claw.
As the name implies, night lizards are mostly active at night, hiding in the rocky crevices or under brush and leafy debris during the day. Their light-sensitive eyes have vertically elliptical pupils. Developing embryos are nourished by a primitive placenta while in the mother's oviduct. Young are born tail first and alive.
There are three specie of Night Lizards in the U.S.
Found in southern California into Baja California.
Found on the San Clemente, Santa Barbara, and San Nicholas islands of the coast of southern California.
Found in soutyhern Nevada, southern Utah, and west and central Arizona through southern California into Mexico.