Lizards are fast, and usually small: most species are no longer than 50 cm, their tail included. Only few species reach a length of more than 1m. Some lizards have body-protrusions such as spines, crests, horns, collars or glide-wings. They originated in the Triassic, but distinct fossils are only known from the Jurassic. Because they are cold-blooded, they like to take sun-baths to be warmed up. There are also lizards that only have front legs and some groups are completely legless. Such lizards can easily be confused with snakes. No wonder snakes originated from a group of lizards.