Ophryacus

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: Viperoidea

Familia: Viperidae
Subfamilia: Crotalinae
Genus: Ophryacus
Species: O. melanurus - O. undulatus –
Name

Ophryacus (Cope, 1887)
Vernacular names
English: Mexican Pit Vipers

Ophryacus is a genus of venomous pit vipers endemic to Mexico. The name is derived from the Greek word ophrys, which means "brow", and the Latin word acus, which means "needle", an allusion to the characteristic horn-like scales over the eyes.[2] Currently, three species are recognized and no subspecies.[3]

Description

The larger of the two species, O. undulatus, grows to between 55 and 70 cm (22 and 28 in) in length. They are characterized by the presence of a single scale over the eye that takes the shape of either a long and relatively slender spine, or a flattened horn. Often, other supraocular scales are also shaped in such a way that they project slightly.[2]
Geographic range

They are restricted to the mountains of eastern, central and southern Mexico.[1]
Species
Species[3] Taxon author[3] Common name[2] Geographic range[1]
O. smaragdinus Grünwald, Jones, Franz-Chávez & Ahumada-Carrillo, 2015 Emerald Horned Pitviper Eastern Mexico.
O. sphenophrys (L. Müller, 1924) Broad-horned Pitviper The mountains of Oaxaca.
O. undulatusT (Jan, 1859) Slender-horned Pitviper The mountains of central and southern Mexico (Hidalgo, Veracruz, Oaxaca, and Guerrero) west of the Isthmus of Tehuantepec at elevations of 1800–2800 m (5,900–9200 feet).

T) Type species.[1]
References

McDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).
Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. ISBN 0-8014-4141-2.

"Ophryacus". Integrated Taxonomic Information System. Retrieved 4 November 2006.