Colubridae (, commonly known as colubrids , from la, coluber, 'snake') is a
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of
snake
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more ...
s. With 249 genera, it is the largest snake family. The earliest species of the family date back to the
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...
epoch. Colubrid snakes are found on every continent except Antarctica.
Description
While most colubrids are not
venom
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 st ...
ous (or have venom that is not known to be harmful to humans) and are mostly harmless, a few groups, such as genus ''
Boiga
''Boiga'' is a large genus of rear-fanged, mildly venomous snakes, known commonly as cat-eyed snakes or simply cat snakes, in the family Colubridae. Species of the genus ''Boiga'' are native to southeast Asia, India, and Australia, but due to ...
'', can produce medically significant injuries. In addition, the
boomslang
The boomslang (, , or ; ''Dispholidus typus'') is a large, highly venomous snake in the family Colubridae.
Taxonomy and etymology
Its common name means "tree snake" in Afrikaans and Dutch – ''boom'' meaning "tree", and ''slang'' meaning "sna ...
, the twig snakes, and the Asian genus '' Rhabdophis'' have caused human fatalities.
Some colubrids are described as opisthoglyphous (often called "rear-fanged"), meaning they have elongated, grooved teeth located in the back of their upper jaws. It is likely that opisthoglyphous dentition evolved many times in the history of snakes and is an evolutionary precursor to the fangs of vipers and elapids, which are located in the front of the mouth.
Classification
In the past, the Colubridae were not a natural group, as many were more closely related to other groups, such as elapids, than to each other. This family was historically used as a " wastebasket taxon" for snakes that do not fit elsewhere. Until recently, colubrids were basically colubroids that were not elapids,
viperids
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 fang ...
, or ''
Atractaspis
:''Common names: burrowing vipers, burrowing asps, mole vipers, Spawls S, Branch B (1995). ''The Dangerous Snakes of Africa: Natural History, Species Directory, Venoms and Snakebite''. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. . more.' ...
''.
However, recent research in molecular phylogenetics has stabilized the classification of historically "colubrid" snakes and the family as currently defined is a
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
, although additional research will be necessary to sort out all the relationships within this group. As of May 2018, eight subfamilies are recognized.
Pseudoxenodontinae
Pseudoxenodontinae is a small subfamily of colubroid snakes, sometimes referred to as a family (Pseudoxenodontidae). They are found in southern and southeastern Asia, from northeast India to southern China (including Taiwan) and south into Indon ...
– two genera
Dipsadinae – 100 genera (sometimes given as family
Dipsadidae
Dipsadinae is a large subfamily of colubroid snakes, sometimes referred to as a family (Dipsadidae). They are found in most of the Americas, including the West Indies, and are most diverse in South America. There are more than 700 species.
Dips ...
These taxa have been at one time or another classified as part of the Colubridae, but are now either classified as parts of other families, or are no longer accepted because all the species within them have been moved to other (sub)families.
*Subfamily Aparallactinae (now a subfamily of
Lamprophiidae
The Lamprophiidae are a family of snakes found throughout much of Africa, including the Seychelles. There are 89 species as of July 2022.
Biology
Lamprophiids are a very diverse group of snakes. Many are terrestrial but some are fossorial (e.g. ...
, sometimes combined with
Atractaspidinae
The Atractaspididae (atractaspidids) are a family of venomous snakes found in Africa and the Middle East, commonly called mole vipers, stiletto snakes, or burrowing asps. Currently, 12 genera are recognized.
Description
This family includes many ...
)
*Subfamily Boiginae (now part of Colubrinae)
*Subfamily
Boodontinae
Boodontinae is a subfamily of colubrid snakes.
Genera
It contains 22 genera.
*'' Boaedon''
*'' Bothrolycus''
*'' Bothrophthalmus''
*'' Buhoma''
*'' Chamaelycus''
*'' Dendrolycus''
*'' Dipsina''
*'' Dromophis''
*'' Duberria''
*'' Gonionotophis''
...
(some of which now treated as subfamily Grayiinae of the new Colubridae, others moved to family
Lamprophiidae
The Lamprophiidae are a family of snakes found throughout much of Africa, including the Seychelles. There are 89 species as of July 2022.
Biology
Lamprophiids are a very diverse group of snakes. Many are terrestrial but some are fossorial (e.g. ...
as part of subfamilies
Lamprophiinae
Lamprophiinae is a subfamily of lamprophiid snakes, a large group of mostly African snakes, most of which were formerly classified as colubrids but which we now know are actually more closely related to elapids.
Lamprophiine snakes are small t ...
,
Pseudaspidinae
Pseudaspididae is a small family (biology), family of Elapoidea, elapoid snakes. They were formerly placed as a subfamily of the Lamprophiidae, but have been more recently identified as a distinct family.
They have a disjunct distribution; two ...
and
Pseudoxyrhophiidae
The Pseudoxyrhophiidae is a family of elapoid snakes, found mostly in Madagascar. They were formerly placed as a subfamily of the Lamprophiidae, but have been more recently identified as a distinct family.
It contains about 22 genera in two ...
, which are now sometimes treated as families)
*Subfamily Dispholidinae (now part of Colubrinae)
*Subfamily Homalopsinae (now family
Homalopsidae
The Homalopsidae are a family of snakes which contains about 28 genera and more than 50 species. They are commonly known as Indo-Australian water snakes, mudsnakes, or bockadams. They are also known as ''ular air'' (lit. "water snake") in Indon ...
)
*Subfamily Lamprophiinae (now a subfamily of Lamprophiidae)
*Subfamily Lycodontinae (now part of Colubrinae)
*Subfamily Lycophidinae (now part of Lamprophiidae)
*Subfamily Pareatinae (now family Pareidae, sometimes incorrectly spelled Pareatidae)
*Subfamily Philothamninae (now part of Colubrinae)
*Subfamily Psammophiinae (now a subfamily of Lamprophiidae)
*Subfamily Pseudoxyrhophiinae (now a subfamily of Lamprophiidae)
*Subfamily Xenoderminae (now family
Xenodermidae
Xenodermidae is a family of snakes native to East Asia, South Asia, and Southeast Asia. All species in the family Xenodermidae are small or moderately sized snakes, never more than but typically less than in total length (including tail). ...
, sometimes incorrectly spelled Xenodermatidae)
*Subfamily
Xenodontinae
Xenodontinae is a subfamily of snakes in the family Colubridae.
The subfamily Xenodontinae encompasses a number of rear-fanged (opisthoglyphous), mildly venomous snake genera found in South America and the Caribbean. Members of the subfamily Xen ...
Dipsadidae
Dipsadinae is a large subfamily of colubroid snakes, sometimes referred to as a family (Dipsadidae). They are found in most of the Americas, including the West Indies, and are most diverse in South America. There are more than 700 species.
Dips ...
)
Fossil record
The Pliocene (
Blancan
The Blancan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 4,750,000 to 1,806,000 years BP, a period of .Ringold Formation of Adams County, Washington has yielded fossils from a number of colubrids including '' Elaphe pliocenica'', '' Elaphe vulpina'', ''
Lampropeltis getulus
''Lampropeltis getula'', commonly known as the eastern kingsnake,Roger Conant (herpetologist), Conant R (1975). ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition''. (First published in 1958). Boston: ...
'', ''
Pituophis catenifer
:''Common name: Pacific gopher snake, coast gopher snake, western gopher snake, Wright AH, Wright AA. 1957. ''Handbook of Snakes of the United States and Canada''. 2 volumes. Comstock Publishing Associates. (7th printing, 1985). 1,105 pp. . (''Pit ...