Caenophidia

The Caenophidia are a derived clade of alethinophidian snakes, which contains over 80% of all the extant species of snakes.[1] The largest family is Colubridae, but it also includes at least seven other families[1], at least four of which were once classified as "Colubridae" before molecular phylogenetics helped us understand their relationships. It has been found to be monophyletic.[1]

Caenophidia
Western diamondback rattlesnake (Crotalus atrox)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Clade:	Afrophidia
Clade:	Caenophidia Hoffstetter, 1939
Subclades
†Anomalophioidea †Russellophioidea Acrochordoidea Colubroides
Synonyms
Xenophidia

Although the Caenophidia previously was held to exclude Acrochordidae, researchers have recognized that acrochordids share several traits with the other caenophidians.[2] Hence Caenophidia is usually considered to comprise Acrochordidae plus more the more derived snakes classified as Colubroidea. Recent molecular studies have also found the families Xenophidiidae and Bolyeriidae to be closely related to caenophidians, forming the sister group to Caenophidia rather than being part of Henophidia.[3][4]

Below is a phylogeny of the Caenophidia based on analyses from several studies:[5][3][4]

Bolyerioidea   Xenophidiidae     Bolyeriidae     Caenophidia     †Anomalophiidae           †Russellophiidae       Acrochordoidea   †Nigerophiidae       Acrochordidae     †Palaeophiidae   †Archaeophinae     †Palaeophiinae           Colubroides     Xenodermidae     Colubriformes   Pareidae   Pareinae     Xylophiinae           Viperidae   Viperinae       Azemiopinae     Crotalinae               Homalopsidae       Elapoidea   Prosymnidae       Buhoma       Psammophiidae   Pseudaspidinae     Psammophiinae             Lamprophiidae   Pseudoxyrhophiinae       Micrelapiinae       Psammodynastiinae     Lamprophiinae             Elapidae   Calliophiinae       Micrurinae       Najinae       Bungarinae       Elapsoidea     Hydrophiinae             Atractaspididae   Cyclocorinae     Atractaspidinae                 Colubroidea Colubridae     Grayiinae     Calamariinae         Ahaetuliinae     Colubrinae             Sibynophiidae     Natricidae         Pseudoxenodontidae     Dipsadidae   Carphophiinae       Xenodontinae     Dipsadinae

References

1. Vidal, Nicolas; Delmas, Anne-Sophie; David, Patrick; Cruaudd, Corinne; Couloux, Arnaud; Hedges, S. Blair (2007). "The phylogeny and classification of caenophidian snakes inferred from seven nuclear protein-coding genes". Comptes Rendus Biologies. 330 (2): 182–187. doi:10.1016/j.crvi.2006.10.001. PMID 17303545.
2. Rieppel, O. (1979). "A cladistics classification of primitive snakes based on skull structure". Zeitschrift für Zoologie, Systematik und Evolutionforschung (Journal of Zoological Systematics and Evolutionary Research). 17 (2): 140–150. doi:10.1111/j.1439-0469.1979.tb00696.x.
3. Reynolds, RG; Niemiller, ML; Revell, LJ (2014). "Toward a Tree-of-Life for the boas and pythons: multilocus species-level phylogeny with unprecedented taxon sampling" (PDF). Molecular Phylogenetics and Evolution. 71: 201–213. doi:10.1016/j.ympev.2013.11.011. PMID 24315866. Archived from the original (PDF) on 2015-12-02. Retrieved 2019-03-04.
4. Figueroa, A.; McKelvy, A. D.; Grismer, L. L.; Bell, C. D.; Lailvaux, S. P. (2016). "A species-level phylogeny of extant snakes with description of a new colubrid subfamily and genus". PLOS ONE. 11 (9): e0161070. Bibcode:2016PLoSO..1161070F. doi:10.1371/journal.pone.0161070. PMC 5014348. PMID 27603205.
5. Pyron; Burbrink; Wiens (2013). "A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes". BMC Evolutionary Biology. 13: 93. doi:10.1186/1471-2148-13-93. PMC 3682911. PMID 23627680.