Common names: pitless vipers, true vipers, Old World

Old World

The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....

 vipers, true adders.

The Viperinae, or viperines, are a subfamily of 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...

 viper

Viperidae

The Viperidae are a family of venomous snakes found all over the world, except in Antarctica, Australia, Ireland, Madagascar, Hawaii, various other isolated islands, and above the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four...

s found in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 and Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

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

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...

. Currently, 12 genera and 66 species are recognized. Most are tropical and subtropical, although one species, Vipera berus

Vipera berus

Vipera berus, the common European adder or common European viper, is a venomous viper species that is extremely widespread and can be found throughout most of Western Europe and all the way to Far East Asia. Known by a host of common names including Common adder and Common viper, adders have been...

, even occurs within the Arctic Circle

Arctic Circle

The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....

.

Description

Members of this subfamily range in size from Bitis schneideri

Bitis schneideri

Bitis schneideri is a venomous viper species found in a small coastal region that straddles the border between Namibia and South Africa. This is the smallest species in the genus Bitis and possibly the world's smallest viperid...

, that grows to a maximum of 28 cm, to Bitis gabonica

Bitis gabonica

Bitis gabonica is a venomous viper species found in the rainforests and savannas of Sub-Saharan Africa. This is not only the largest member of the genus Bitis, but also the world's heaviest viperid and it has the longest fangs ,and the highest venom yield of any venomous snake...

 that reaches a maximum length of over 2 m. Most species are terrestrial, but a few, such as Atheris

Atheris

Atheris is a genus of venomous vipers found only in tropical subsaharan Africa, excluding southern Africa. Confined to rain forest areas, many members have isolated and fragmented distributions. In an interesting example of convergent evolution, they show many similarities to the arboreal pit...

, are completely arboreal.

Although the heat-sensing pits that characterize the Crotalinae

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...

 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 of the skin between the supranasal and nasal scales and is connected to the ophthalmic branch of the trigeminal nerve. The nerve endings here resemble those in the labial pits of boas. The supernasal sac is present in Daboia

Daboia

Daboia is a monotypic genus of venomous Old World viper. The single species, D. russelii, is found in Asia throughout the Indian subcontinent, much of Southeast Asia, southern China and Taiwan...

, Pseudocerastes

Pseudocerastes

Pseudocerastes is a monotypic genus created for a venomous viper species, P. persicus. This species is found throughout the Middle East and as far east as Pakistan, but not on the African mainland. Often referred to as the false horned viper because of the hornlike structures above their eyes that...

 and Causus

Causinae

The Causinae are a monotypic subfamily of venomous vipers found only in subsaharan Africa. It was created for the genus Causus; a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus and the fact that they have round...

, but is especially well developed in Bitis

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 involves inflating and deflating their bodies while hissing and puffing loudly. The...

. 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

Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 and Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

. However, they do not occur in Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

.

Reproduction

Generally, members of this subfamily are viviparous (ovoviviparous

Ovoviviparity

Ovoviviparity, ovovivipary, or ovivipary, is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch...

), although a few, such as Pseudocerastes

Pseudocerastes

Pseudocerastes is a monotypic genus created for a venomous viper species, P. persicus. This species is found throughout the Middle East and as far east as Pakistan, but not on the African mainland. Often referred to as the false horned viper because of the hornlike structures above their eyes that...

, lay eggs.

Genera

Genus	Taxon author	Species	Subsp.*	Common name	Geographic range
Adenorhinos Adenorhinos Adenorhinos is a monotypic genus created for a venomous viper species, A. barbouri. This is a small and exceptionally rare terrestrial species found only in the Uzungwe and Ukinga mountains of south-central Tanzania in Africa. No subspecies are recognized.-Description:A small species reaching only...	Loveridge, 1930	1	0	Uzungwe viper	Central Tanzania Tanzania The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state... : Udzungwe and Ukinga Mountains.
Atheris Atheris Atheris is a genus of venomous vipers found only in tropical subsaharan Africa, excluding southern Africa. Confined to rain forest areas, many members have isolated and fragmented distributions. In an interesting example of convergent evolution, they show many similarities to the arboreal pit...	Cope Edward Drinker Cope Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen... , 1862	8	1	Bush vipers	Tropical subsaharan Africa Sub-Saharan Africa Sub-Saharan Africa as a geographical term refers to the area of the African continent which lies south of the Sahara. A political definition of Sub-Saharan Africa, instead, covers all African countries which are fully or partially located south of the Sahara... , excluding southern Africa Southern Africa Southern Africa is the southernmost region of the African continent, variably defined by geography or geopolitics. Within the region are numerous territories, including the Republic of South Africa ; nowadays, the simpler term South Africa is generally reserved for the country in English.-UN... .
Bitis 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 involves inflating and deflating their bodies while hissing and puffing loudly. The...	Gray John Edward Gray John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray .... , 1842	14	2	Puff adders	Africa Africa Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...  and the southern Arabian Peninsula Arabian Peninsula The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2... .
Cerastes Cerastes (genus) Cerastes is a genus of small, venomous vipers found in the deserts and semi-deserts of northern North Africa eastward through Arabia and Iran. Three species are currently recognized.-Description:...	Laurenti Josephus Nicolaus Laurenti Josephus Nicolaus Laurenti was an Austrian naturalist of Italian origin.Laurenti is considered the auctor of the class Reptilia through his authorship of on the poisonous function of reptiles and amphibians... , 1768	3	0	Horned vipers	North Africa North Africa North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...  eastward through Arabia Arabian Peninsula The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...  and Iran Iran Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia... .
Daboia Daboia Daboia is a monotypic genus of venomous Old World viper. The single species, D. russelii, is found in Asia throughout the Indian subcontinent, much of Southeast Asia, southern China and Taiwan...	Gray John Edward Gray John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray .... , 1842	1	1	Russell's viper	Pakistan Pakistan Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan... , India India India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world... , Sri Lanka Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the... , Bangladesh Bangladesh Bangladesh , officially the People's Republic of Bangladesh is a sovereign state located in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south... , Nepal Nepal Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India... , Myanmar Myanmar Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south.... , Thailand Thailand Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the... , Cambodia Cambodia Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia... , China China Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...  (Kwangsi and Kwangtung), Taiwan Taiwan Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...  and Indonesia Indonesia Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...  (Endeh, Flores Flores Flores is one of the Lesser Sunda Islands, an island arc with an estimated area of 14,300 km² extending east from the Java island of Indonesia. The population was 1.831.000 in the 2010 census and the largest town is Maumere. Flores is Portuguese for "flowers".Flores is located east of Sumbawa... , east Java Java Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java... , Komodo Komodo (island) Komodo is one of the 17,508 islands that make up the Republic of Indonesia. The island has a surface area of 390 km² and over 2000 inhabitants. The inhabitants of the island are descendants of former convicts who were exiled to the island and who have mixed themselves with the Bugis from... , Lomblen Islands).
Echis Echis Echis is a genus of venomous vipers found in the dry regions of Africa, the Middle East, Pakistan, India and Sri Lanka. They have a characteristic threat display, rubbing sections of their body together to produce a "sizzling" warning sound...	Merrem Blasius Merrem Blasius Merrem was a German naturalist.Merrem was born at Bremen, and studied at the university of Göttingen under Johann Friedrich Blumenbach. He developed an interest in zoology, particularly ornithology... , 1820	8	6	Saw-scaled vipers	India India India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...  and Sri Lanka Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the... , parts of the Middle East Middle East The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...  and Africa Africa Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...  north of the equator.
Eristicophis Eristicophis Eristicophis is a monotypic genus created for a venomous viper species, E. macmahonii. It is found only in the desert region of Balochistan near the borders of Iran, Pakistan and Afghanistan. No subspecies are currently recognized.-Description:...	Alcock Alfred William Alcock Alfred William Alcock was a British physician naturalist and carcinologist.Alcock was the son of a sea-captain, John Alcock in Bombay, India who retired to live in Blackheath...  and Finn, 1897	1	0	McMahon's viper	The desert region of Balochistan Balochistan (region) Balochistan or Baluchistan is an arid, mountainous region in the Iranian plateau in Southwest Asia; it includes part of southeastern Iran, western Pakistan, and southwestern Afghanistan. The area is named after the numerous Baloch tribes, Iranian peoples who moved into the area from the west...  near the Iran Iran Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia... -Afghanistan Afghanistan Afghanistan , officially the Islamic Republic of Afghanistan, is a landlocked country located in the centre of Asia, forming South Asia, Central Asia and the Middle East. With a population of about 29 million, it has an area of , making it the 42nd most populous and 41st largest nation in the world... -Pakistan Pakistan Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...  border.
Macrovipera Macrovipera Macrovipera is a genus of venomous vipers that inhabit the semideserts and steppes of North Africa, the Near and Middle East, and the Milos Archipelago in the Aegean Sea. These snakes are responsible for a number of bites in Africa and western Asia every year...	Reuss, 1927	4	4	Large Palearctic Palearctic The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth's surface.Physically, the Palearctic is the largest ecozone...  vipers	Semideserts and steppes of northern Africa North Africa North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and... , the Near Near East The Near East is a geographical term that covers different countries for geographers, archeologists, and historians, on the one hand, and for political scientists, economists, and journalists, on the other...  and Middle East Middle East The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East... , and the Milos Archipelago Milos Milos , is a volcanic Greek island in the Aegean Sea, just north of the Sea of Crete...  in the Aegean Sea Aegean Sea The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus... .
Montatheris Montatheris Montatheris is a monotypic genus created for a venomous viper species, M. hindii. This is a small terrestrial species found only at high altitude on Mount Kenya and the Aberdare mountain range in Kenya. No subspecies are currently recognized....	Boulenger George Albert Boulenger George Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:... , 1910	1	0	Kenya mountain viper	Kenya Kenya Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east... : moorlands of the Aberdare Aberdare Range The Aberdare Range is a 160 km long mountain range of upland, north of Kenya's capital Nairobi with an average elevation of . It is located in west central Kenya, northeast of Naivasha and Gilgil and just south of the Equator...  range and Mount Kenya Mount Kenya Mount Kenya is the highest mountain in Kenya and the second-highest in Africa, after Kilimanjaro. The highest peaks of the mountain are Batian , Nelion and Point Lenana . Mount Kenya is located in central Kenya, just south of the equator, around north-northeast of the capital Nairobi...  above 3000 m.
Proatheris Proatheris Proatheris is a monotypic genus created for a venomous viper species, P. superciliaris. This is a small terrestrial species found in Tanzania, Malawi and Mozambique. No subspecies are currently recognized.-Description:...	Peters Wilhelm Peters Wilhelm Karl Hartwich Peters was a German naturalist and explorer.He was assistant to Johannes Peter Müller and later curator of the Berlin Zoological Museum. In September 1842 he travelled to Mozambique via Angola. He returned to Berlin with an enormous collection of natural history specimens... , 1854	1	0	Lowland viper	Floodplains from southern Tanzania (northern end of Lake Malawi Lake Malawi Lake Malawi , is an African Great Lake and the southernmost lake in the Great Rift Valley system of East Africa. This lake, the third largest in Africa and the eighth largest lake in the world, is located between Malawi, Mozambique, and Tanzania... ) through Malawi Malawi The Republic of Malawi is a landlocked country in southeast Africa that was formerly known as Nyasaland. It is bordered by Zambia to the northwest, Tanzania to the northeast, and Mozambique on the east, south and west. The country is separated from Tanzania and Mozambique by Lake Malawi. Its size...  to near Beira Beira, Mozambique Beira is the second largest city in Mozambique. It lies in the central region of the country in Sofala Province, where the Pungue River meets the Indian Ocean. Beira had a population of 412,588 in 1997, which grew to an estimated 546,000 in 2006... , central Mozambique Mozambique Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest... .
Pseudocerastes Pseudocerastes Pseudocerastes is a monotypic genus created for a venomous viper species, P. persicus. This species is found throughout the Middle East and as far east as Pakistan, but not on the African mainland. Often referred to as the false horned viper because of the hornlike structures above their eyes that...	Boulenger George Albert Boulenger George Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:... , 1896	1	1	False horned viper	From the Sinai of Egypt Egypt Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...  eastward to Pakistan Pakistan Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan... .
Vipera Vipera Vipera is a genus of venomous vipers. It has a very wide range, being found from North Africa to just within the Arctic Circle and from Great Britain to Pacific Asia. The name is possibly derived from the Latin words vivus and pario, meaning "alive" and "bear" or "bring forth"; likely a reference... T	Laurenti Josephus Nicolaus Laurenti Josephus Nicolaus Laurenti was an Austrian naturalist of Italian origin.Laurenti is considered the auctor of the class Reptilia through his authorship of on the poisonous function of reptiles and amphibians... , 1768	23	12	Palearctic vipers	Great Britain Great Britain Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...  and nearly all of continental Europe Continental Europe Continental Europe, also referred to as mainland Europe or simply the Continent, is the continent of Europe, explicitly excluding European islands....  across the Arctic Circle Arctic Circle The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....  and on some islands in the Mediterranean (Elba Elba Elba is a Mediterranean island in Tuscany, Italy, from the coastal town of Piombino. The largest island of the Tuscan Archipelago, Elba is also part of the National Park of the Tuscan Archipelago and the third largest island in Italy after Sicily and Sardinia... , Montecristo Montecristo Montecristo is a small Italian islet, approximately 4.3 kilometers across at its widest point, located about halfway between Corsica and mainland Italy; south of Elba and west of Giglio. It is part of the Tuscan Archipelago... , Sicily Sicily Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,... ) and Aegean Sea Aegean Sea The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...  eastward across northern Asia Asia Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...  to Sakhalin Island and North Korea North Korea The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea... . Also found in northern Africa North Africa North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...  in Morocco Morocco Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara... , Algeria Algeria Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...  and Tunisia Tunisia Tunisia , officially the Tunisian RepublicThe long name of Tunisia in other languages used in the country is: , is the northernmost country in Africa. It is a Maghreb country and is bordered by Algeria to the west, Libya to the southeast, and the Mediterranean Sea to the north and east. Its area... .

• ) Not including the nominate subspecies.
  

^T) Type genus

Type genus

In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...

.

Taxonomy

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

Viperidae

The Viperidae are a family of venomous snakes found all over the world, except in Antarctica, Australia, Ireland, Madagascar, Hawaii, various other isolated islands, and above the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four...

, that separate subfamilies were created for them:

• Genus Azemiops - moved to subfamily Azemiopinae
  Azemiopinae
  Azemiopinae is a monotypic subfamily created for the monotypic genus, Azemiops, that contains the venomous viper species Azemiops feae, described here. No subspecies are recognized. The first specimen was collected by Italian explorer Leonardo Fea, and was described as a new genus and new species...
  
   by Liem, Marx & Rabb (1971).
• Genus Causus - recognition of subfamily Causinae
  Causinae
  The Causinae are a monotypic subfamily of venomous vipers found only in subsaharan Africa. It was created for the genus Causus; a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus and the fact that they have round...
  
   (Cope, 1860) was proposed by Groombridge (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 Atheris

Atheris

Atheris is a genus of venomous vipers found only in tropical subsaharan Africa, excluding southern Africa. Confined to rain forest areas, many members have isolated and fragmented distributions. In an interesting example of convergent evolution, they show many similarities to the arboreal pit...

, Adenorhinos

Adenorhinos

Adenorhinos is a monotypic genus created for a venomous viper species, A. barbouri. This is a small and exceptionally rare terrestrial species found only in the Uzungwe and Ukinga mountains of south-central Tanzania in Africa. No subspecies are recognized.-Description:A small species reaching only...

, Montatheris

Montatheris

Montatheris is a monotypic genus created for a venomous viper species, M. hindii. This is a small terrestrial species found only at high altitude on Mount Kenya and the Aberdare mountain range in Kenya. No subspecies are currently recognized....

 and Proatheris

Proatheris

Proatheris is a monotypic genus created for a venomous viper species, P. superciliaris. This is a small terrestrial species found in Tanzania, Malawi and Mozambique. No subspecies are currently recognized.-Description:...

, the type genus

Type genus

In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...

for which is Atheris.