Dipsadinae is a large

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 botanical subfamily names with "-oideae", and zo ...

of colubroid

snakes Snakes are elongated Limbless vertebrate, limbless reptiles of the suborder Serpentes (). Cladistically Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales much like other members of ...

, sometimes referred to as a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

(Dipsadidae).

Species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of the subfamily Dipsadinae are found in most of the

Americas The Americas, sometimes collectively called America, are a landmass comprising the totality of North America and South America.''Webster's New World College Dictionary'', 2010 by Wiley Publishing, Inc., Cleveland, Ohio. When viewed as a sing ...

, including the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

, and are most diverse in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. There are more than 700 member species. Dipsadinae are an ecologically and morphologically diverse group of mostly small to moderate-sized snakes, typically less than in total length. Some are arboreal, but others are aquatic or terrestrial and may even burrow. Most are

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

. Many eat frogs or lizards, and some consume mammals and birds. Several genera (e.g. ''

Adelphicos ''Adelphicos'' is a genus of New World burrowing snakes in the family Colubridae. The genus consists of nine species. Geographic range Species of the genus ''Adelphicos'' can be found in Mexico and northern Central America (Belize and Guatemala ...

'', ''

Atractus ''Atractus'' is a genus of Colubridae, colubrid ground snakes in the subfamily Dipsadinae. The genus includes more than 140 distinct species. Geographic range Snakes of the genus ''Atractus'' are Endemism, endemic to Central America, Central an ...

'', ''

Geophis ''Geophis'' is a genus of snakes in the subfamily Dipsadinae of the family (biology), family Colubridae of the Taxonomic rank, superfamily Colubroidea. Species in the genus ''Geophis'' are Common name, commonly referred to as Latin American eart ...

'', ''

Dipsas ''Dipsas'' is a genus of nonvenomous New World snakes in the subfamily Dipsadinae of the family Colubridae. The genus ''Sibynomorphus'' has been moved here. Species of the genus ''Dipsas'' are known as snail-eaters. Taxonomy The genus ''Dipsas'' ...

'', '' Ninia'', ''

Sibon Sibon () is a village in Khurgam Rural District of Khurgam District, Rudbar County, Gilan province, Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to ...

'', ''

Sibynomorphus ''Dipsas'' is a genus of nonvenomous New World snakes in the subfamily Dipsadinae of the family Colubridae. The genus ''Sibynomorphus'' has been moved here. Species of the genus ''Dipsas'' are known as snail-eaters. Taxonomy The genus ''Dipsas'' ...

'', ''

Tropidodipsas ''Tropidodipsas'' is a genus of New World snakes in the subfamily Dipsadinae of the family Colubridae. Geographic range Species of the genus ''Tropidodipsas'' are found in Mexico and Central America. Species Eight species are recognized as bein ...

'') are specialized feeders on gooey and slimy prey, such as frog eggs, earthworms, snails, and slugs. Almost all species are completely harmless to humans, although a few genera (e.g. '' Borikenophis'', '' Cubophis'', ''

Heterodon ''Heterodon'' is a genus of harmless colubrid snakes endemic to North America.Platt, Dwight R. 1983. Heterodon'. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles, 351: 1-2. They are stout with upt ...

'', '' Hydrodynastes'', ''

Philodryas ''Philodryas'' is a genus of colubrid snakes endemic to South America, commonly called green snakes. Description Species in the genus ''Philodryas'' share the following characters: Head distinct from neck, with distinct ''canthus rostralis'' ...

'') have inflicted painful bites with local, non-life-threatening symptoms.

Evolution

Molecular evidence indicates that Dipsadidae originated in Asia during the

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

, about 50 Ma. Xenodontinae and Dipsadinae diverged once the family had reached

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

in the Middle Eocene, with the latter dispersing to trans-Andean South America in multiple waves between 38 and 20 Ma, whereas the former dispersed to cis-Andean South America about 39 Ma and entered the West Indies some 33 Ma.

Synonymy

Some authors refer to part or all of this group as

Xenodontinae Xenodontinae is a subfamily of snakes in the family Colubridae. Xenodontinae are a highly diverse subfamily of snakes, in which many species may look alike, but are actually very different. Their hemipenial morphology serves as a crucial taxonom ...

, but if the two names are used synonymously, Dipsadinae is the correct name because it is older. When Xenodontinae is used non-synonymously, it normally refers to the larger and more derived South American-Caribbean subclade containing the genus ''

Xenodon ''Xenodon'' is a genus of New World snakes in the subfamily Dipsadinae of the family Colubridae. Geographic range Species of the genus ''Xenodon'' are found in Mexico, Central America, and South America. Diet Snakes in the genus ''Xenodon'' pre ...

'' and its relatives, whereas Dipsadinae ''sensu stricto'' is restricted to the smaller and more basal Central American subclade containing the genus ''

'' and its relatives. Also, a third North American group (sometimes called "Carphophiinae") contains nine species in five genera at the base of the Dipsadinae (the "North American relicts" thought to have descended from the ancestors of dipsadines as they crossed from Asia to South America by way of North America; genera ''

'', '' Farancia'', ''

Diadophis ''Diadophis punctatus'', commonly known as the ring-necked snake or ringneck snake, is a small, harmless species of colubrid snake found throughout much of the United States, as well as south in Central Mexico and as far north as Quebec, Canada. ...

'', '' Carphophis'', and ''

Contia ''Contia'' is a small genus of small snakes in the subfamily Dipsadinae of the family Colubridae. The genus is native to western North America. Etymology The generic name, ''Contia'', is in honor of American entomologist John Lawrence LeConte ...

'').

Genera

Within the Dipsadinae, the three major groups/clades or subfamilies are the Central American group ("Dipsadinae" ''sensu stricto''), the South American + Caribbean group ("

"), and a small North American group (sometimes called the "Carphophiinae" or, incorrectly, "Heterodontinae"). In addition, a number of snake genera are likely to be dipsadines based on their morphology and geographic range, but because of the absence of genetic data and information about their closest relatives, they are considered genera''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' and are not currently placed in a subgroup of the Dipsadinae.

Central American clade ("Dipsadinae" ''sensu stricto'')

South American + Caribbean clade ("Xenodontinae")

North American clade ("Carphophiinae")

Genera ''incertae sedis''

Notes

References

{{Taxonbar, from=Q143402 Dipsadinae Snake families Taxa named by Charles Lucien Bonaparte