The Lacertoidea is a group of lizards that includes the Lacertidae, Teiidae, Gymnophthalmidae, and the burrowing Amphisbaenia. Studies of anatomy have traditionally grouped the lacertoids with skinks; however, more recent studies focusing on DNA have placed them as a distinct group of lizards, more closely related to the venomous Toxicofera. The relationships of the Amphisbaenia to other lizards have long been a mystery; although superficially snakelike, their anatomy and locomotion is quite distinct from that of snakes. However, they do not closely resemble any other group of lizards. Recent molecular studies suggest that amphisbaenians are grouped with the Lacertidae, in a group named the Lacertibaenia.