Common names: Mexican jumping pitviper, jumping viper.

Atropoides nummifer is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 found in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 and Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

. Currently, 3 subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

 are recognized, including the nominate subspecies described here.

Description

Adults are short and exceedingly stout, commonly growing to 18-24 inches (46-61 cm) in length. The snout is rounded with a sharp canthus

Canthus (snake)

In snakes and amphibians, the canthus, canthal ridge or canthus rostralis, is the angle between the flat crown of the head and the side of the head between the eye and the snout. More specifically, between the supraocular scale and the rostral scale. It is defined as a sharp ridge in many viperids,...

.

At midbody there are 23-27 rows of dorsal scales

Dorsal scales

In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales.When counting dorsal scales, numbers are often given for three points along the body, for example 19:21:17...

 that are strongly keeled

Keeled scales

Keeled scales refer to reptile scales that, rather than being smooth, have a ridge down the center that may or may not extend to the tip of the scale, making them rough to the touch...

, tubercular in large specimens. The ventral scales

Ventral scales

In snakes, the ventral scales are the enlarged and transversely elongated scales that extend down the underside of the body from the neck to the anal scale. When counting them, the first is the anteriormost ventral scale that contacts the paraventral row of dorsal scales on either side...

 are 121-135, while the subcaudals are 26-36 and mostly single. The eye is separated from the labial scales by 3-4 rows of small scales.

The color pattern consists of a tan, light brown or gray ground color that is overlaid with a series of around 20 dark brown or black rhomboid blotches. The lower tips of these blotches often connect with spots on the flanks to form narrow crossbands. The top of the head is dark with oblique postorbital stripes, below which the side of the head is a lighter color. The belly is whitish, occasionally with dark brown blotches.

These snakes have sometimes been mistaken for young bushmasters (Lachesis muta

Lachesis muta

Lachesis muta is a venomous pitviper species found in South America. Two subspecies are currently recognized, including the nominate subspecies described here.-Description:...

), but can easily be identified by their lack of a specialized tail tip.

Geographic range

Found in eastern Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 from San Luis Potosí

San Luis Potosí

San Luis Potosí officially Estado Libre y Soberano de San Luis Potosí is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 58 municipalities and its capital city is San Luis Potosí....

 southeastward on the Atlantic versant and lowlands through northern Guatemala

Guatemala

Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...

, southern Belize

Belize

Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...

, Honduras

Honduras

Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...

, Nicaragua

Nicaragua

Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...

 and Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

 to central Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

. On the Pacific versant in disjunct populations from southern Mexico, Guatemala, El Salvador

El Salvador

El Salvador or simply Salvador is the smallest and the most densely populated country in Central America. The country's capital city and largest city is San Salvador; Santa Ana and San Miguel are also important cultural and commercial centers in the country and in all of Central America...

, Costa Rica and Panama. Found in various types of forest, including cloud forest and rain forest at 40-1600 m altitude. The type

Biological type

In biology, a type is one particular specimen of an organism to which the scientific name of that organism is formally attached...

 originally lacked locality information, but apparently "Mexico" was filled in some time later. A restriction to Teapa, Tabasco

Tabasco

Tabasco officially Estado Libre y Soberano de Tabasco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 17 municipalities and its capital city is Villahermosa....

, Mexico, was proposed by Burger (1950).

Conservation status

This species is classified as Least Concern (LC) on the IUCN

World Conservation Union

The International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...

 Red List of Threatened Species

IUCN Red List

The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

 (v3.1, 2001). Species are listed as such due to their wide distribution, presumed large population, or because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend is stable. Year assessed: 2007.

Subspecies

Subspecies	Taxon author	Common name	Geographic range
A. n. mexicanus Atropoides nummifer mexicanus Atropoides nummifer mexicanus is a venomous pitviper subspecies found in Mexico and Central America as far south as Panama.-Description: Adults grow to an average of 50–70 cm in length. The maximum length is 86.7 cm for males and 97.9 cm for females...	(Duméril, Bibron Gabriel Bibron Gabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...  & Duméril, 1854)	Central American jumping pitviper	Type locality: Cobán, Alta Verapaz, Guatemala Guatemala Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast... .
A. n. nummifer	(Rüppell, 1845)	Mexican jumping pitviper	Type locality: Mexico Mexico The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of... .
A. n. occiduus Atropoides nummifer occiduus Atropoides nummifer occiduus is a venomous pitviper subspecies found in southern Mexico, Guatemala and El Salvador.-Description:Adults are usually 35–60 cm in length. The largest specimens reported are a male of 74.8 cm from Baja Verapaz and a female of 79.5 cm from Volcán de Agua,...	(Hoge, 1966)	Guatemalan jumping pitviper	Type locality: San Augustín, Guatemala.