Florida Wormlizard: Rhineuridae

Florida wormlizards, the only living species in this family, are long and thin creatures without legs. They have thin rings circling their round bodies, no ear openings, and usually no visible eyes. This combination of features makes many people confuse them with earthworms. Florida wormlizards, however, have scales, and worms do not. In fact, it is the scales on the wormlizard's head that cover its eyes. The head is hard and somewhat flattened with a bladelike front edge, which helps the lizard to dig into the soil. The upper jaw sticks out farther than the lower jaw, so the animal has an overbite of sorts. The shape of the head has caused some people to call them shovelnose wormlizards. They are usually a pearly pinkish white color, but some individuals may be tinted slightly orange-pink. Their heads and tail tips are sometimes a bit darker. Like most snakes, they shed their skin—actually just the top layer of skin—in one piece.

Adults can grow to about one-half inch (1.2 centimeters) around at the middle of the body and reach 9.5 to 11 inches (24 to 28 centimeters) long, including a short tail. The tail begins at the vent, a slit-like opening on the underside of the animal, and is only about one-tenth of the total length of the wormlizard. The tail, which is slightly flattened, is covered on top with little cone-shaped bumps called tubercles (TOO-ber-kuls).

Inside the body, Florida wormlizards look much like other types of wormlizards, which are all grouped together under the name amphisbaenians (am-fizz-BAY-nee-ens). The amphisbaenians include four different families of wormlizards: the Rhineuridae, or Florida wormlizards; the Bipedidae, or mole-limbed wormlizards; the Trogonophidae, or spade-headed wormlizards; and Amphisbaenidae, which are known simply as worm lizards. The Florida wormlizard is the only amphisbaenian that naturally lives in the United States. The others live in Africa, Central and South America, and a few places in Europe and Asia. All amphisbanians are long, thin reptiles that look much like worms, but with scales. They have an odd ear set-up in which parts of the ear attach to tissue on the sides of the face. When the ground vibrates, the tissue senses the vibrations and sends them on to the ear, so the animal can actually hear the ground move. In addition, amphisbaenians have two lungs like almost all other vertebrates (pronounced VER-teh-brehts), which are animals with backbones, but one of their lungs is either extremely small or missing altogether. This arrangement works well in these species, and indeed in many snakes, that have very thin bodies without room for two side-by-side lungs. They also have a forked tongue, no visible ear holes, and one center tooth in the front of the upper jaw that is bigger than the other teeth. The Florida wormlizards sometimes have one little tooth on either side of the center tooth. Florida wormlizards also have their nostrils toward the bottom of the head rather than on the top as many other reptiles do.