Trimorphodon

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Cladus: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Infraclassis: Lepidosauromorpha
Superordo: Lepidosauria
Ordo: Squamata
Subordo: Serpentes
Infraordo: Caenophidia
Superfamilia: Colubroidea

Familia: Colubridae
Subfamilia: Colubrinae
Genus: Trimorphodon
Species (7): T. biscutatus – T. lambda – T. lyrophanes – T. paucimaculatus – T. quadruplex – T. tau – T. vilkinsonii
Name

Trimorphodon Cope, 1861: 297

Type species: Lycodon lyrophanes Cope, 1860, by original designation.
References
Primary references

Cope, E.D. 1861. Contributions to the Ophiology of Lower California, Mexico and Central America. Proceedings of the Academy of Natural Sciences of Philadelphia 13: 292–306. BHL Reference page.

Additional references

Devitt, T.J., LaDuc, T.J. & McGuire, J.A. 2008. The Trimorphodon biscutatus (Squamata: Colubridae) Species Complex Revisited: A Multivariate Statistical Analysis of Geographic Variation. Copeia 2008(2): 370-387. DOI: 10.1643/CH-07-045 Reference page.

Links

Uetz, P. & Hallermann, J. 2021. Trimorphodon . The Reptile Database. Accessed on 25 May 2018.

Vernacular names
Deutsch: Lyraschlange
English: Lyre Snakes

Trimorphodon is a genus of mildly venomous, rear-fanged, colubrid snakes. They are commonly known as lyre snakes, named after the distinctive V shaped pattern on their head that is said to resemble the shape of a lyre. In Mexico, they are commonly called "víbora de uña," or "nail viper."[2] The word Trimorphodon is a combination of three Greek words, 'tri' - three, 'morph' - shape, and 'odon' - teeth, which refers to the three distinct kinds of teeth that lyre snakes have: recurved anterior teeth; shorter middle teeth, and large grooved fangs at the rear of the jaw. There are two distinct species in the genus Trimorphodon, with seven subspecies.

Range

Trimorphodon biscutatus ranges throughout the southwestern United States, from Texas to California as well as into northern Mexico. Trimorphodon tau ranges through most of Mexico, and down into Central America, in Guatemala, El Salvador, Honduras, Nicaragua, and as far south as Costa Rica. They are primarily found in rocky crevices and outcroppings.
Description

Lyre snakes usually grow to about 1m at adult size. They have a broad head with a narrow neck and large eyes with vertical pupils. They are tan or brown in color, with distinctive black or dark brown bands that have lighter colored borders.
Behavior

Trimorphodon species are primarily nocturnal, and feed on lizards, rodents and even bats. They are a very secretive species, and excellent climbers. They live inside rock crevices and canyon walls where humans cannot easily find them, which makes research difficult.
Reproduction

They are oviparous, laying clutches of 10 or more eggs. Hybridization between species is not unknown in the areas where their range overlaps.
Speed

There is no information on this category.
Venom

Their venom is not considered to be dangerous to humans.
Species

Western lyre snake, Trimorphodon biscutatus (Duméril, Bibron & Duméril, 1854)
Sonoran lyre snake, Trimorphodon lambda (Cope, 1886)
Baja California lyre snake, Trimorphodon lyrophanes (Cope, 1860)
Sinaloan lyre snake, Trimorphodon paucimaculatus Taylor, 1938
Trimorphodon quadruplex (Smith, 1941)
Mexican lyre snake, Trimorphodon tau
Trimorphodon tau latifascia (Peters, 1869)
Trimorphodon tau tau (Cope, 1870)
Texas lyre snake, Trimorphodon vilkinsonii (Cope, 1886)

References

Wright, A.H. and A.A. Wright. 1957. Handbook of Snakes of the United States and Canada. Comstock. Ithaca and London.

SOS SIERRA LOS HUICHOLES, JALISCO[permanent dead link]. Under "Listado de Fauna"

Genus Trimorphodon at The Reptile Database
CaliforniaHerps.com Trimorphodon biscutatus lyrophanes - Baja California Lyresnake