Metlapilcoatlus

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: Metlapilcoatlus
Species (5): M. indomitus – M. mexicanus – M. nummifer – M. occiduus – M. olmec
Name

Metlapilcoatlus Campbell, Frost & Castoe, 2019: 52

Type species: Atropos mexicanus Duméril, Bibron & Duméril, 1854, by original designation.

References
Primary references

Campbell, J.A., Frost, D.R. & Castoe, T.A. 2019. A new generic name for jumping pitvipers (Serpentes: Viperidae). Revista Latinoamericana de Herpetología 2(2): 52–53. PDF Reference page.

Links

Uetz, P. & Hallermann, J. 2021. Mixcoatlus . The Reptile Database. Accessed on 22 May 2021.

Metlapilcoatlus is a genus of venomous pit vipers endemic to Mexico and Central America. Six species are currently recognized. The common names suggest they are able to leap at an attacker, but this is likely exaggerated. Common names for the species include jumping pitvipers[2] and jumping vipers.[3]

Description

All of these snakes are extremely thick-bodied, with M. nummifer being the most stout. The head is large, with small eyes and a broadly rounded snout. The tail is short, not prehensile, and accounts for only 15% of the total length.[2]

The color pattern usually consists of a gray-brown or reddish brown ground color (sometimes yellow, cream, purplish brown or black), overlaid with a series of lateral and dorsal blotches. The shape of these blotches is subject to some variation, but is sometimes still helpful for identification.[2]
Geographic range

Found in the mountains of eastern Mexico southeastward on the Atlantic versant and lowlands though Central America to central Panama. On the Pacific versant, they occur in isolated populations in east-central and southern Mexico, Guatemala, El Salvador, Costa Rica and Panama.[1]
Behavior

The common name alludes to the supposed ability these snakes have to launch themselves at an attacker during a strike, thereby bridging a distance that is equal to or greater than the length of the body.[2] Mehrtens (1987) states that they live up to their name, striking at their assailants with such force that they actually leave the ground.[3] Campbell and Lamar (2004), on the other hand, describe this as greatly exaggerated, saying that actually these snakes are only able to strike about half of their own body length. In addition, they describe them as slow moving and non-aggressive. However, when provoked all species will put on a rather dramatic open-mouthed threat display.[2]

These snakes may be active both during the day and at night. On the other hand, populations found at higher altitudes seem to be active only during daylight hours and never at night.[2]
Feeding

Adults feed mainly on small mammals and lizards, while juveniles feed on orthopterans and skinks.[2]
Venom

Unlike most vipers, members of this genus will strike and then hold on and chew. In one case, a machete was used to pry off the jaws. March (1929) wrote that M. mexicanus (M. nummifer) will hang on and make half a dozen punctures unless quickly and forcibly removed. However, the effects of the venom include only transient pain and mild swelling. In one part of Honduras the locals even insist that the snake (M. nummifer) is not venomous. Laboratory studies suggest that Metlapilcoatlus venoms are unlikely to lead to consumption coagulopathy and incoagulable blood in humans.
Species

Species^[4]	Taxon author^[4]	Common name^[2]	Geographic range^[1]
M. borealis^[5]	Tepos-Ramírez et al., 2021	Boreal jumping pit viper	Mexico on the Sierra Madre Oriental, South of San Luis Potosi to Hidalgo and North of Veracruz.
M. indomitus	Smith & Ferrari-Castro, 2008	Botaderos jumping pit viper	Sierra de Botaderos and La Muralla of Honduras.
M. mexicanus	Duméril, Bibron & Duméril, 1854	Central American jumping pit viper	Southern Mexico, Belize, Guatemala, Honduras, Nicaragua, Costa Rica, El Salvador, Panama.
M. nummifer	Rüppell, 1845	Mexican jumping pit viper	Mexico, South of Veracruz to Oaxaca, Chiapas, Puebla.
M. occiduus	Hoge, 1966	Guatemalan jumping pit viper	Mexico, Guatemala, El Salvador.
M. olmec	Pérez-Higareda, H.M. Smith & Juliá-Zertuche, 1985	Tuxtlan jumping pit viper	Mexico on the upper slopes of the Sierra de Los Tuxtlas in southern Veracruz.

*) Not including the nominate subspecies.
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.
Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X.
"Atropoides". Integrated Taxonomic Information System. Retrieved 2 November 2006.

Tepos-Ramírez M, Flores-Villela F, Velasco JA, Pedraza-Lara P, García-Rubio OR, Jadin RJ. 2021. Molecular Phylogenetics and Morphometrics Reveal a New Endemic Jumping Pitviper (Serpentes: Viperidae: Metlapilcoatlus) from the Sierra Madre Oriental of Mexico. Journal of Herpetology. 55(2): 81-191. June 2021