Slender Glass Lizard

Ophisaurus attenuatus (Cope, 1880)

slender glass lizard
Slender glass lizard, Will Co., IL photo by Mike Redmer

Key Characters: Limbs absent; dark longitudinal stripes flank a noticeable groove on each side of the body.

Similar Species: May be distinguished from snakes by the presence of movable eyelids and external ear openings.  See Key to Lizards of Illinois for help with identification.

Subspecies: Two subspecies are recognized; Western Slender Glass Lizard, Oaattenuatus and Eastern Slender Glass Lizard. O. a. longicaudus McConkey, 1952. The former is found in Illinois.

slender glass lizard
Slender glass lizard, St. Louis Co., MO photo by Chris Phillips

Description: A long (up to 90 cm TL), slender lizard with yellow to brown back sporting six longitudinal stripes, including a distinct middorsal stripe. White flecks in the middle of the scales sometimes form light stripes.

Habitat: Prairies, sand prairies, old fields, and dry open woodlands.

Natural History: Known as the glass lizard because of the easily broken tail. Glass lizards eat invertebrates and small lizards. Mating occurs in May and 5 to 15 eggs are laid in late June or July. Hatchlings range from 10 to 13 cm TL. Hawks and carnivorous mammals are the main predators.

Status: The slender glass lizard is not listed as threatened in Illinois although it is seldom encountered. Listed as a Species in Greatest Need of Conservation in the Illinois Wildlife Action Plan.

Etymology: Ophisaurus – ophis (Greek) meaning serpent, reptile; sarous (Greek) meaning lizard, reptile; attenuatus – (Latin) meaning tapered, drawn out, thin.

Original Description: Cope, E.D. 1880. On the zoological position of Texas. Bulletin of the US National Museum.  17:1-51.

Type Specimen: Neotype, USNM 15537

Type Locality: “Dallas, Texas”

Original Name: Opheosaurus ventralis attenuatus Cope, 1880

Nomenclatural History: First named as a subspecies of Oventralis, but recognized by Boulenger (1885. Cat. Lizards British Mus. Vol. 2) as a full species, even though Cope’s stance on the matter continued to influence many herpetologists until Neil (1949. Herpetologica 5(4):97-100) provided evidence that attenuatus was a full species.  Kennicott (1855. Cat. Animals Cook Co. IL. State Ag. Soc. Trans. 1853-1854, 1:577-95) referred to Illinois specimens of Oattenuatus as Olineatus (Gray, 1838), a junior synonym for Oventralis.