The Colubroides are a
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
in the suborder Serpentes (
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 ...
).
It contains over 85% of all the extant species of snakes.
The largest family is
Colubridae
Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...
, but it also includes at least six other families,
at least four of which were once classified as "Colubridae" before
molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
helped in understanding their relationships.
It has been found to be
monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
.
Morphological
synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to ...
are defined as such from Zaher et al. (2009):
Loss of the right carotid artery Carotid artery may refer to:
* Common carotid artery, often "carotids" or "carotid", an artery on each side of the neck which divides into the external carotid artery and internal carotid artery
* External carotid artery, an artery on each side of ...
; intercostal arteries arising from the dorsal aorta throughout the trunk at intervals of several body segments; specialized expanded costal cartilages; presence of a muscle protractor laryngeus; separate muscle protractor quadrati; separate spinalis and semispinalis portion in the epaxial trunk; spinules or spines covering the hemipenial body.
Traditionally, the name "
Colubroidea
Colubroidea is a superfamily of snakes in the clade Colubroides that includes Colubridae, with some studies splitting Colubridae into multiple families that make up Colubroidea. Historically, Colubroidea also included other caenophidian snakes su ...
" was used for this clade. This was seen problematic, however, as many of the same studies that support this clade of snakes also advocated for the various subfamilies of
Colubridae
Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...
to be reevaluated as proper families in their own right.
As the result of this, Zaher et al. (2009) proposed to rename the clade as "Colubroides", restricting Colubroidea to the clade
Colubridae
Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...
and several related families that were formerly colubrid subfamilies.
Below is a phylogeny of colubroid snakes found in many analyses:
References
{{Taxonbar, from=Q65080051
Alethinophidia