Xenophidia
Encyclopedia
Xenophidia is a superfamily
of the suborder Serpentes (snake
s) that contains cobra
s, viper
s, sea snakes and the majority of snake
species. Almost all venomous snakes belong to this superfamily. Additionally, the broad belly scales and rows of dorsal scales correspond to the vertebrae in Caenophidians, while they do not in Henophidians or Scolecophidians.
Caenophidia contains most of the diversity of extant snakes, with over 3,000 species
. They are believed to be a recent (Greek prefix caeno- = recent) evolutionary radiation
, having evolved in the mid-Cenozoic
.
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
of the suborder Serpentes (snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s) that contains cobra
Cobra
Cobra is a venomous snake belonging to the family Elapidae. However, not all snakes commonly referred to as cobras are of the same genus, or even of the same family. The name is short for cobra capo or capa Snake, which is Portuguese for "snake with hood", or "hood-snake"...
s, 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, sea snakes and the majority of snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
species. Almost all venomous snakes belong to this superfamily. Additionally, the broad belly scales and rows of dorsal scales correspond to the vertebrae in Caenophidians, while they do not in Henophidians or Scolecophidians.
Caenophidia contains most of the diversity of extant snakes, with over 3,000 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...
. They are believed to be a recent (Greek prefix caeno- = recent) evolutionary radiation
Evolutionary radiation
An evolutionary radiation is an increase in taxonomic diversity or morphological disparity, due to adaptive change or the opening of ecospace. Radiations may affect one clade or many, and be rapid or gradual; where they are rapid, and driven by a single lineage's adaptation to their environment,...
, having evolved in the mid-Cenozoic
Cenozoic
The Cenozoic era is the current and most recent of the three Phanerozoic geological eras and covers the period from 65.5 mya to the present. The era began in the wake of the Cretaceous–Tertiary extinction event at the end of the Cretaceous that saw the demise of the last non-avian dinosaurs and...
.
Families
- AtractaspididaeAtractaspididaeThe Atractaspididae are a family of snakes found in Africa and the Middle East. Currently, 12 genera are recognized.-Description:This family includes many genera formerly classed in other families, on the basis of fang type. It includes fangless , rear-fanged , fixed-fanged , and viper-like species...
(mole vipers). - Colubridae (rear-fanged snakes).
- ElapidaeElapidaeElapidae is a family of venomous snakes found in tropical and subtropical regions around the world, terrestrially in Asia, Australia, Africa, North America and South America and aquatically in the Pacific and Indian Oceans...
(cobraCobraCobra is a venomous snake belonging to the family Elapidae. However, not all snakes commonly referred to as cobras are of the same genus, or even of the same family. The name is short for cobra capo or capa Snake, which is Portuguese for "snake with hood", or "hood-snake"...
s, mambaMambaMambas, of the genus Dendroaspis , are a group of highly venomous, fast-moving land-dwelling snakes of Africa. They belong to the family of Elapidae which includes cobras, coral snakes, taipans, brown snakes, tiger snakes, death adders, kraits and, debatably, sea snakes...
s, coral snakeCoral snakeThe coral snakes are a large group of elapid snakes that can be subdivided into two distinct groups, Old World coral snakes and New World coral snakes...
s and kraits). - Hydrophiidae (sea snakes).
- ViperidaeViperidaeThe 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...
(viperViperidaeThe 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, pit vipers and rattlesnakeRattlesnakeRattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae . There are 32 known species of rattlesnake, with between 65-70 subspecies, all native to the Americas, ranging from southern Alberta and southern British Columbia in Canada to Central...
s).