Reptiles Database

Order Squamata
Suborder Amphisbaenia

Family Bipedidae (Two-legged Worm Lizards)


Bipes biporus
© Wayne van Devender

Appearance: While all other amphisbaenians have lost their limbs, members of the family Bipedidae have retained their forelimbs (bi = two; pes, latin = foot). In fact, they even develop supernumerary phalanges on their forelimbs which are used for burrowing.

Diagnosis: Fused fronto-parietal complex, anteriorly shifted pectoral girdle and forelimbs, polyphalangy of digit I (after Kearney 2003).

Size: 12-26 cm snout-vent length.

Distribution: The family with its single genus Bipes is restricted to Mexico. Some authors reported Bipes from the southwestern United states but they have never be confirmed.

Habitat: burrowing in desert soil.

Behavior: no information available.

Reproduction: oviparous with small ctutches of one to four eggs.

Phylogenetic relationships: See the Amphisbaenidae page for a phylogenetic tree that includes the Bipedidae.

Only one genus:

Reference:

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

Macey, J. Robert; Theodore J. Papenfuss; Jennifer V. Kuehl; H. Mathew Fourcade and Jeffrey L. Boore (2004)
Phylogenetic relationships among amphisbaenian reptiles based on complete mitochondrial genomic sequences.
Molecular Phylogenetics and Evolution 33 (1): 22-31

Papenfuss, T. J. (1982)
The ecology and systematics of the amphisbaenian genus Bipes.
OCCASIONAL PAPERS OF THE CALIFORNIA ACADEMY OF SCIENCES (No. 136): 1-42

Saint,K.M.; Austin,C.C.; Donnellan,S.C. & Hutchinson,M.N. 1998
C-mos, a nuclear marker useful for squamate phylogenetic analysis.
Molecular Phylogenetics and Evolution 10 (2): 259-263

Zug,G.R.; Vitt, L.J. & Caldwell, J.P. (2001)
Herpetology, 2nd ed.
Academic Press San Diego, London, [...]XIV + 630 pp.