Eryx (snake)

Eryx is a genus of nonvenomous snakes, commonly known as Old World sand boas, in the subfamily Erycinae of the family Boidae. Species of the genus are found in southeastern Europe, northern Africa, the Middle East, and southwestern Asia. Thirteen species are recognized as being valid.

Description
The genus Eryx has the following characters. The head is not distinct from the neck. The dorsal surface of the head is covered with small scales. The rostral is large. The eyes range from small to very small, and the pupils are vertical. The anterior maxillary teeth and anterior mandibular teeth are longer than the posterior ones. The body is almost cylindrical. The dorsal scales are smooth or keeled. The tail is very short, either not prehensile or only slightly prehensile. The subcaudals are undivided.

Distribution and habitat
Species of snakes of the genus Eryx are found in southeastern Europe, northern Africa, the Middle East, and southwestern Asia.

Species
Nota bene: In the list below, a taxon author in parentheses indicates that the species was originally described in a genus other than Eryx.

T ) Type species.
 * ) Not including the nominate subspecies.

Fossil taxa
Two fossil species are known. The earliest is E. linxiaensis from the Miocene of Gansu, China, which appears to be the sister species to Eryx colubrinus, suggesting several intercontinental dispersals from Africa to Eurasia during the Miocene. E. primitivus is known from the middle Pliocene of Spain, and appears to be an early offshoot of the main Eryx lineage.