basic logo

A Guide to the Amphibians
and Reptiles of California

Trimorphodon biscutatus lyrophanes - Baja California Lyresnake

Click on a picture for a larger view

Range in California: Red

Green: Sonoran Lyresnake

observation link

Adult, San Diego County Adult, San Diego County
Adult, San Diego County Adult, San Diego County
Adult, San Diego County
Adult, San Diego County
Juvenile, San Diego County. © Gary Nafis. Specimen courtesy of Tim Burkhardt
Adult, San Diego County
Adult, San Diego County
Adult, Santa Barbara County
© Patrick Briggs
Adult, San Bernardino County © Patrick Briggs
Adult, San Bernardino County
© Richard Cazares
Adult, San Bernardino County, west of the Providence Mountains.
© Brad Sillasen
Snake shown to the left, showing the undivided anal plate.
© William Flaxington
Adult, San Diego County
© Michael Clarkson
Adult, east of the Granite Mountains, San Bernardino County. © Keith Condon Adult, San Diego County mountains.
© Stuart Young
Adult, San Diego County © Bruce Edley  
Habitat, San Diego County
Habitat, San Diego County
Habitat, San Diego County Habitat, Riverside County
Habitat, San Bernardino County.
© William Flaxington
Habitat, coastal San Diego County
Habitat, Lava Flow,
San Bernardino County
Habitat, San Diego County
Short Video
A lyre snake coils up defensively and strikes. A lyre snake crawls up a steep rock outcrop at night. A lyre snake shows off its rock climbing skills at night in San Diego County. I put the video camera on the dashboard one night while road cruising a rocky pass in San Diego County and eventually a lyre snake showed up on the road. It might look like I stopped in the middle of the road, but actually I drove ahead and parked safely before running back to film the snake from closer up.

Mildly Venomous
One of the larger rear-fanged snakes, but considered harmless to humans, but handle with caution, as some people have had unpleasant reactions to this snake's bite.
Trimorphodon biscutatus have been recorded from 18 - 47 3/4 inches in length (46 - 121 cm). Most snakes encountered are 24 - 36 inches long (61 - 91 cm).
A slender snake with a broad head well-differentiated from the slim neck. Coloring closely matches a snake's rocky habitat, from gray to light brown. There are usually about 35 dorsal blotches with light edges and a pale crossbar in the center, and smaller irregular blotches on the lower sides. A lyre-shaped marking is present on top of the head. The pupils are vertical, like those of a cat. The underside is off-white or yellowish with dark spots. The anal plate is usually undivided.
According to Stebbins there is a dark form of this snake with a light brown middorsal stripe found at the Pisgah lava flow.
Nocturnal, active in very dry conditions as well as during rains. Terrestrial, and good climbers. This snake often searches rock crevices for prey. It can be found during the day inside crevices in large rock outcrops, as well as crossing desert roads at night.
Primarily lizards, but also known to eat small mammals, nestling birds, and snakes.
Not well known. Lyre snakes apparently originated in the tropics, where breeding is year round, and the northern races may have retained this capability.
In California, this snake occurs from around Santa Barbara County northeast into Inyo County, and south along the coast into Baja California, in two strips through the peninsular ranges, and along the Colorado River, splitting around the Imperial Valley. It is also absent from a large area of the Mojave Desert except for isolated localities including the Pisgah lava flow area. This may be due to the secretive nature of this snake. It may be more widespread in this area.
Associated primarily with rocky locations in desert scrub and grassland, chaparral, oak woodland, coniferous forest, but found in rockless areas, also.
Taxonomic Notes
Some researchers do not recognize any subspecies of Trimorphodon biscutatus.

The former subspecies T. b. vandenburghi was synonymized with T. b. lyrophanes in 1994 (Grismer et al. (1994 Bull. So,. California Acad. Sci. 93: 45-80).

Devitt et al, in a 2008 paper, recommended the subspecies T. b. lambda be recognized as a distinct species, Trimorphodon lambda - Sonoran Lyre Snake.
Conservation Issues  (Conservation Status)

Family Colubridae Colubrids
Genus Trimorphodon Lyresnakes
Species biscutatus Lyresnake

lyrophanes Baja California Lyresnake
Original Description
Trimorphodon biscutatus - (Dumeril, Bibron and Dumeril, 1854) - Erpet. Gen., Vol. 7, Pt. 2, p. 1153
Trimorphodon biscutatus lyrophanes - Cope, 1860

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Trimorphodon - Greek - tri - three, and morph - shape, and odon- teeth - refers to the 3 tooth shapes in the upper jaw, recurved anterior teeth; the shorter middle teeth and elongate, grooved fangs at the rear.
- Latin - bis - two, and scutatus- plated - refers to the doubled loreal plate
lyrophanes - Greek - lyro - lyre, and phaneros - visible - probably refers to they lyre-like pattern on the head

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
Trimorphodon biscutatus - Western Lyre Snake (no subspecies recognized)

Formerly called California Lyre Snake - T. b. vandenburghii

Related or Similar California Snakes
T. b. lambda - Sonoran Lyresnake
Great Basin Gopher Snake
San Diego Gopher Snake
Desert Glossy Snake
California Glossy Snake

More Information and References
Natureserve Explorer

California Dept. of Fish and Game

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., and F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Snakes of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Bartlett, R.D. , & Alan Tennant. Snakes of North America - Western Region. Gulf Publishing Co., 2000.

Brown, Philip R. A Field Guide to Snakes of California. Gulf Publishing Co., 1997.

Ernst, Carl H., Evelyn M. Ernst, & Robert M. Corker. Snakes of the United States and Canada. Smithsonian Institution Press, 2003.

Wright, Albert Hazen & Anna Allen Wright. Handbook of Snakes of the United States and Canada. Cornell University Press.

Devitt, Thomas J., Travis J. LaDuc, and Jimmy A. McGuire. The Trimorphodon biscutatus (Squamata: Colubridae) Species Complex Revisited: A Multivariate Statistical Analysis of Geographic Variation. Copeia. 2008 (2): 370-387.
Conservation Status

The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.

This snake is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.
Status Listing
U.S. Endangered Species Act (ESA) None
California Endangered Species Act (CESA) None
California Department of Fish and Game None
Bureau of Land Management None
USDA Forest Service None
Natureserve Global Conservation Status Ranks
World Conservation Union - IUCN Red List


Home Site Map About Us Identification Lists Maps Photos More Lists CA Snakes CA Lizards CA Turtles CA Salamanders CA Frogs
Contact Us Usage Resources Rattlesnakes Sounds Videos FieldHerping Yard Herps Behavior Herp Fun CA Regulations
Beyond CA All Herps

Return to the Top

© 2000 - 2012