The Crotalinae, commonly known as pit vipers, or pit adders, are a subfamily of vipers found in Asia and the Americas. Like all other vipers, they are venomous. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 23 genera and 155 species are recognized: These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is Crotalus, of which the type species is the timber rattlesnake, C. horridus.
Agkistrodon is a genus of venomous pit vipers commonly known as American moccasins. The genus is endemic to North America, ranging from the Southern United States to northern Costa Rica. Eight species are currently recognized, all of them monotypic and closely related. Common names include: cottonmouths, copperheads, and cantils.
The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous and have long, hinged fangs that permit deep penetration and injection of their venom. Three subfamilies are currently recognized. They are also known as viperids. The name "viper" is derived from the Latin word vipera, -ae, also meaning viper, possibly from vivus ("living") and parere, referring to the trait viviparity common in vipers like most of the species of Boidae.
Gloydius is a genus of venomous pitvipers endemic to Asia, also known as Asian moccasins or Asian ground pit vipers. Named after American herpetologist Howard K. Gloyd, this genus is very similar to the North American genus Agkistrodon. 24 species are currently recognized.
Bitis is a genus of venomous vipers found in Africa and the southern Arabian Peninsula. It includes the largest and the smallest vipers in the world. Members are known for their characteristic threat displays that involve inflating and deflating their bodies while hissing and puffing loudly. The type species for this genus is B. arietans, which is also the most widely distributed viper in Africa. Currently, 18 species are recognized.
Field's horned viper is a species of snake in the family Viperidae. The species is native to the deserts of the Middle East. Like all other vipers, it is venomous. It was previously considered a subspecies of the Persian horned viper. The main differences between this species and the Persian horned viper are in scalation and venom composition.
Atheris is a genus of vipers known as bush vipers. They are found only in tropical subsaharan Africa and many species have isolated and fragmented distributions due to their confinement to rain forests. Like all other vipers, they are venomous. In an example of convergent evolution, they show many similarities to the arboreal pit vipers of Asia and South America. Seventeen species are currently recognized.
Causus is a genus of vipers found only in sub-Saharan Africa. It is a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus, and because they have round pupils. However, this is contradicted by recent molecular studies. Seven species are currently recognized. They are commonly known as night adders. Like all other vipers, they are venomous.
Atheris barbouri is a small and rare species of terrestrial viper endemic to the Uzungwe and Ukinga mountains of south-central Tanzania in Africa.
Proatheris is a monotypic genus created for the viper species, Proatheris superciliaris. This is a small terrestrial species endemic to East Africa. Like all other vipers, it is venomous. No subspecies are currently recognized.
Montatheris is a monotypic genus created for the viper species, Montatheris hindii, which also known by the common names Kenya mountain viper, Kenya montane viper, montane viper, and Hind's viper. Like all other vipers, M. Hindii is venomous. This is a small terrestrial species endemic to Kenya. There are no subspecies which are currently recognized as being valid.
Pseudocerastes is a genus of vipers endemic to the Middle East and Asia. It was originally created as a monotypic genus in 1896 by Boulenger for the species Pseudocerastes persicus, but three species are now recognised: the spider-tailed horned viper ; Persian horned viper and Field's horned viper. Like all other vipers, the members of this genus are venomous.
Atheris nitschei is a species of venomous snake, a viper in the subfamily Viperinae of the family Viperidae. The species is native to Africa. There are no subspecies that are recognized as being valid.
Atheris anisolepis, otherwise known as the Mayombe bush-viper, is a species of viper endemic to west-central Africa. No subspecies are currently recognized. The Atheris anisolepis is very similar to the Atheris squamigera but it is differentiated by the complete row of scales between the supralabial scales and the ocular scales as well as having enlarged, smooth, and/or weekly keeled scales. However, this differentiation does not always apply and may not always be accurate.
The Albany adder is a viper species. It was previously considered a subspecies of Bitis cornuta. Its range is restricted to eastern and southern Cape Province in South Africa. Like all vipers, it is venomous.
Bitis worthingtoni, also known commonly as the Kenya horned viper and the Kenyan horned viper, is a species of venomous snake in the subfamily Viperinae of the family Viperidae. The species is endemic to Kenya. There are no subspecies that are recognized as being valid.
Bothriechis marchi, also known as Honduran palm pit viper and March's palm pit viper, is a species of pitviper, a venomous snake, in the subfamily Crotalinae of the family Viperidae. The species is endemic to Central America. There are no subspecies that are recognized as being valid.
Craspedocephalus brongersmai, also known commonly as Brongersma's pit viper, is a species of venomous snake in the subfamily Crotalinae of the family Viperidae. The species is native to islands off the west coast of Sumatra, Indonesia. No subspecies are currently recognized.
The spider-tailed horned viper is a species of viper, a venomous snake, in the family Viperidae and genus Pseudocerastes. The genus is commonly known as "false-horned vipers".
