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.[3]
Distribution and habitat
Species of snakes of the genus Eryx are found in southeastern Europe, northern Africa, the Middle East, and southwestern Asia.[1]
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.
From the northern Caucasus and the north coast of the Caspian Sea east through Kazakhstan to the north coast of the Aral Sea and Lake Balkhash, though the Zaysan Valley to Sinkiang in China and southern Mongolia. Also in northern and eastern Iran, Afghanistan and western Pakistan.
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.[5][6]
^Boulenger GA (1893). Catalogue of the Snakes in the British Museum (Natural History). Volume I., Containing the Families ... Boidæ .... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 448 pp. + Plates I–XXVIII. (Genus Eryx, p. 122–123, Figure 7).
Daudin FM (1803). Histoire Naturelle, Génerale et Particulière des Reptiles; Ouvrage faisant suite aux Œuvres de Leclerc de Buffon, et partie du Cours complet d'Histoire naturelle rédigé par C.S. Sonnini, membre de plusieurs Sociétés savantes. Tome septième [Volume 7]. Paris: F. Dufart. 436 pp. (Eryx, new genus, pp. 251–253). (in French).