Bipes biporus (Cope 1894) extant, 15-23 cm often referred to as the Mexican mole lizard, is an elongated burrowing lizard with forelimbs only. Bipes was a sister to Tamaulipasaurus.

Distinct from Tamaulipasaurus, the skull of Bipes had no jugal. The internal nares opened further anteriorly. As in Gymnophthalmus, the medial finger is missing, but the metacarpal is retained. Digits II and III were subequal with IV and V progressively smaller. Only a tiny femur remains of the hind limb. The tail is extremely short.

Diplometopon zarudnyi (Nikolsky 1907, 30cm) is the extant Zarudny's worm lizard found in the Arabian peninsula.

Amphibamus alba (Linneaus 1758) is the extant white worm lizard, a burrowing skink related to Bipes and Dibamus. It is an omnivore. The skulls of Amphisbaena (above left) and Bipes (above right).

Dibamus novaeguineae (Dumeril and Bibron 1839) is a blind, worm-like, legless lizard with a wide skull. Often a "wild card" in phylogenetic analyses, here it nests between Spathorhynchus and Bipes. The skull appears to be bent at mid length. The pterygoids are narrow and widely separated.

Black and white image from Digimorph.org and used with permission.

Cope ED 1894. On the genera and species of Euchirotidae. American Naturalist 28: 436-437.

Duméril AMC and Bibron G 1839. Erpétologie Générale (ten volumes)

Kearney M 2003. Systematics of the Amphisbaenia (Lepidoauria: Squamata) based on morphological evidence from recent and fossil forms. Herpetological Monographs 2003 17(1): 1-74.

Nikolsky A 1907. Reptiles et amphibiens recueillis (part.) M. N. A. Zarudny en Perse en 1903-1904 [in Russian and Latin]. Ann. Mus. Zool. Acad. Imp. Sci., St. Petersburg 10 [1905]: 260-301 - online here

Papenfuss TJ 1982. The Ecology and Systematics of the Amphisbaenian Genus Bipes. Occasional papers of the California Academy of Science 136: 1-42.

wiki/Amphisbaenia
wiki/Bipes
wiki/Dibamus
wiki/Diplometopon