structural:summarization
Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs. Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating. They have a rigidly fused skull, lack pterygoid teeth and external ears. Their eyes are greatly reduced, and covered with a scale. They are small insectivorous lizards, with long, slender bodies, adapted for burrowing into the soil. They usually lay one egg with a hard, calcified shell, rather than the leathery shells typical of many other reptile groups. The family Dibamidae has two genera, Dibamus with 23 species native to Southeast Asia, Indonesia, the Philippines, and western New Guinea and the monotypic Anelytropsis native to Mexico. Recent phylogenetic analyses place the dibamids as the sister clade to all the other lizards and snakes or classify them as sharing a common ancestor with the infraorder Gekkota, with Dibamidae and Gekkota forming the sister clade to all other squamates. Hoeckosaurus from the Oligocene of Mongolia represents the only fossil record of the group.