Typical Blind Snakes

The Typhlopidae are a family of blind snakes. They are found mostly in the tropical regions of Africa, Asia, the Americas, and all mainland Australia and various islands. The rostral scale overhangs the mouth to form a shovel-like burrowing structure. They live underground in burrows, and since they have no use for vision, their eyes are mostly vestigial. They have light-detecting black eye spots, and teeth occur in the upper jaw. Typhlopids do not have dislocatable lower jaw articulations restricting them to prey smaller than their oral aperture. All species in the family Typhlopidae are fossorial and feed on social fossorial invertebrates such as termites and ants. The tracheal lung is present and chambered in all species. One species, the Brahminy’s blind snake, is the only unisexual snake, with the entire population being female and reproducing via parthenogenesis. The tail ends with a horn-like scale. Most of these species are oviparous. Currently, 18 genera are recognized containing over 200 species.

Description

The total length of most species ranges from 7 to 28 cm, with maximum recorded sizes reaching 97 cm. The snout is distinctly protruding, and the head shields are specialized for a burrowing lifestyle. The skull is dense and compact, with reduced kinesis compared to more evolutionarily advanced snakes. The mouth is positioned on the ventral surface of the head. In some species, the eye region is externally indistinguishable.

The body shows clear adaptations to a fossorial life. The body covered with smooth, rounded scales. Dorsal and ventral scales are of equal size. The tail is very short and thick, ending in a sharp spine. The strongly reduced eyes are visible only as dark spots beneath the thick horny shields.

The premaxillary and maxillary bones do not make contact. The premaxillary, palatine, and mandibular bones lack teeth, while the maxillary bones bear a few small teeth at their posteroinferior ends. The nasal bones are broadly connected with the frontal and prefrontal bones. Supratemporal bones are absent.

All genera retain vestiges of the pelvis, and in some species rudimentary hindlimbs are also present.