Anelytropsis Dibamus †Hoeckosaurus Anelytropidae Cope, 1885 Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs.

[1] Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating.

[10] Dibamids are burrower lizards characterized by their elongated bodies with blunt head and tail, and an apparent lack of limbs.

[1][2] General characteristics of the soft tissue includes a tongue that is covered in lamellae except in the tip, heavily modified ears without external openings or middle ear cavity or eustachian tubes,[2] and highly reduced eyes that are covered by a scale and lack internal structure, particularly in Dibamus.

[13][14] The combination of fossorial habits and small size, contributes to the development of a skull configuration that is frequently found in other groups of burrowers and miniaturized species.

[13] The main cranial differences, besides sizes, between Anelytropsis and Dibamus is the presence of epipterygoid and postfrontal in the Central American genus.

[12] The family Dibamidae contains two genera, Anelytropsis and Dibamus, and the close relationship of the genera was based on two morphological characteristics that are unique to these groups, the secondary palate and the lamellae covering the tongue, and additional cranial characteristics that can be shared with other groups of lizards.

[2] Dibamids, and particularly Dibamus was considered to be part of geckos and precisely the family of legless geckos;[17] snakes, considering the organization of the skull and jaw muscles;[18] or was proposed to be closely related to a group of fossorial skinks with elongated bodies and reduced limbs.

[6][23][9] Phylogenetic evidence supports dibamids being the most basal squamates, being sister to all other lizards and snakes, and indicates that they diverged during the late Triassic, around 210 million years ago.

[1] According to The Reptile Database,[5] Anelytropsis is monotypic and Dibamus includes 23 species: Anelytropsis[24] Dibamus[25] For additional details, see here An extinct monotypic genus, Hoeckosaurus was recently proposed from the description of fossil material from the early Oligocene of the Valley of Lakes in Central Mongolia.

[1] Biogeographical studies suggest that the separation between Anelytropsis and Dibamus, specifically the clade with species that are distributed in continental South East Asia, occurred approximately 69 million years ago during the late Cretaceous and the migration from Asia to North America took place during the Late Paleocene or Eocene through Beringia.