The Viperinae, or viperines, are a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

viper The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs tha ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

and

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

. They are distinguished by their lack of the heat-sensing pit organs that characterize their

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

, the subfamily

Crotalinae The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...

. Currently, 13

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

are recognized. Most are

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

, although one species, ''

Vipera berus ''Vipera berus'', the common European adderMallow D, Ludwig D, Nilson G. (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. . or common European viper,Stidworthy J. (1974). ...

'', even occurs within the

Arctic Circle The Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at w ...

. Like all vipers, they are

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

. The common names "pitless vipers", "true vipers", "

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...

vipers",Mallow D, Ludwig D, Nilson G. 2003. ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company, Malabar. 359 pp. . and "true adders"U.S. Navy. 1991. ''Poisonous Snakes of the World''. US Govt. New York: Dover Publications Inc. 203 pp. . all refer to this group.

Description

Members of this subfamily range in size from ''

Bitis schneideri :''Common names: Namaqua dwarf adder, Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Spawls S, Branch B (1995). ''The Dangerous S ...

'', which grows to a maximum total length (body and tail) of , to the

Gaboon viper The Gaboon viper (''Bitis gabonica''), also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa.McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geog ...

, which reaches a maximum total length of over . Most species are

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

, but a few, such as those of the genus ''

Atheris ''Atheris'' is a genus of vipers known as bush vipers.Spawls S, Branch B (1995). ''The Dangerous Snakes of Africa''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . They are found only in tropical subsaharan Africa (excluding southern Afri ...

'', are completely

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

. Although the heat-sensing pits that characterize the

are clearly lacking in the viperines, a supernasal sac with sensory function has been described in a number of species. This sac is an

invagination Invagination is the process of a surface folding in on itself to form a cavity, pouch or tube. In developmental biology, invagination is a mechanism that takes place during gastrulation. This mechanism or cell movement happens mostly in the vegetal ...

of the skin between the supranasal and nasal scales and is connected to the ophthalmic branch of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...

. The nerve endings here resemble those in the labial pits of boas. The supernasal sac is present in the genera ''

Daboia ''Daboia'' is a genus of venomous vipers.. Species The following four species are recognized as being valid: *''Daboia mauritanica'' – Moorish viper *''Daboia palaestinae'' – Palestine viper *''Daboia russelii'' – Russell's viper *''Da ...

'', '' Pseudocerastes'' and ''

Causus ''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. How ...

'', but is especially well developed in the genus ''

Bitis ''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 defl ...

''. Experiments have shown that strikes are not only guided by visual and chemical cues, but also by heat, with warmer targets being struck more frequently than colder ones.

Geographic range

Viperinae are found in Europe, Asia, and Africa,McDiarmid RW, Campbell JA, Touré T. 1999. ''Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1''. Washington, District of Columbia: Herpetologists' League. 511 pp. (series). (volume). but not in

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

.Stidworthy J. 1974. ''Snakes of the World''. New York: Grosset & Dunlap Inc. 160 pp. .

Reproduction

Generally, members of this subfamily are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

, although a few, such as ''Pseudocerastes'', ''

Cerastes The cerastes (Greek: κεράστης, transliteration: ''kerastēs'', meaning "having horns"Echis ''Echis'' (common names: saw-scaled vipers, carpet vipersSpawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .) is a genus of vipers found in the dry regions of Africa, the Middle E ...

'' species are

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

(egg-laying).

Genera

Taxonomy

Until relatively recently, two other genera were also included in the Viperinae. However, they were eventually considered so distinctive within the

Viperidae The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs tha ...

, that separate subfamilies were created for them: * Genus ''Azemiops'' - moved to subfamily '' Azemiopinae'' by

Liem Many ethnic Chinese people have lived in Indonesia for many centuries. Over time, especially under social and political pressure during the New Order era, most Chinese Indonesians have adopted names that better match the local language. History ...

Marx Karl Heinrich Marx (; 5 May 1818 – 14 March 1883) was a German philosopher, economist, historian, sociologist, political theorist, journalist, critic of political economy, and socialist revolutionary. His best-known titles are the 1848 p ...

Rabb Rabb ( ar, رب, ''Rabb'', sometimes "''rabb'' (-i/-u/-a)"), is often used to refer to God in Arabic (''Allah'') as the "Lord" or "master". It is used by adherents of various religions, including Muslims, Christians, Hindus, and Sikhs across the Mi ...

(1971). * Genus ''Causus'' - recognition of subfamily ''

Causinae ''Causus'' is a genus of Viperidae, 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 ...

Cope The cope (known in Latin as ''pluviale'' 'rain coat' or ''cappa'' 'cape') is a liturgical vestment, more precisely a long mantle or cloak, open in front and fastened at the breast with a band or clasp. It may be of any liturgical colours, litu ...

, 1860 was proposed by

Groombridge Groombridge is a village of about 1,600 people. It straddles the border between Kent and East Sussex, in England. The nearest large town is Royal Tunbridge Wells, about away by road. The main part of the village ("New Groombridge") lies in t ...

(1987) and further supported by Cadle (1992). Nevertheless, these groups, together with the genera currently recognized as belonging to the Viperinae, are still often referred to collectively as the true vipers. Broadley (1996) recognized a new tribe, Atherini, for the genera ''

'', '' Adenorhinos'', '' Montatheris'' and ''

Proatheris ''Proatheris'' (commonly referred to as the lowland viper and swamp viper among other names) is a monotypic genus created for the viper species, ''Proatheris superciliaris''. This is a small terrestrial species endemic to East Africa. Like all ...

'', the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal f ...

for which is ''Atheris''.

Description

Geographic range

Reproduction

Genera

Taxonomy

See also

References

Further reading