|The Vertebrates||Pythonomorpha: Colubroidea|
Colubroidea: Earliest advanced snakes.
Links: Higher Reptile Taxa.
currently Africa & Asia
small to medium-sized snakes; blunt-headed; maxilla is extremely reduced; maxilla with elongated, hollow maxillary fang; maxilla has complex articulation with prefrontal; short tails; fossorial; solenoglyphs; oviparous with clutches of 2-11; feed upon newborn rodents and other fossorial reptiles
Links: Atractaspididae; Atractaspididae
Venomous, often marine snakes with hollow, relatively immobile maxillary fangs.
Boiga dendrophila, the mangrove snake. From the Virtual Museum of Natural History, by permission.
All continents except Antarctica (and Australia?), in all but coldest latitudes.
20-400 cm; frequently venomous but without anterior fangs or hollow teeth; venom, where present, mostly proteases; most have rows of teeth that are of equal size; teeth on premaxillae lost; maxilla elongate; basipterygoid processes lost; coronoids lost; pupils round; vertebrae generally lack downward-projecting spines; right common artery lost; pelvic girdle absent; large, strap-like scales in single row down the belly; most terrestrial.
Note: Very speciose taxon, with 85-90% of living species. May be a catch-all taxon for advanced snakes of multiple lineages. ATW021012.
Links: Animal Diversity Web: Family Colubridae; Flying snake home page Colubridae: Chrysopelea); Squamata/COLUBRIDAE/colubridae01.html">Reptilia, Squamata, Ophidia, Colubridae, Nattern (German); Colubridae, Italian); Predacao de anuros pela serpente (Portugese); ????????? ?????? (Colubridae). ????: Colubrids. (Russian); Colubridae; I Colubridi, Colubridae (Italian); APUS.RU - Colubridae Russian); SERPENTS also in Russian); Advanced Snakes pictures & lots of references); Colubridae.html pictures). ATW030128.
Viperidae: adders, vipers, & copperheads.
from the Early Miocene.
Large, triangular heads & stout bodies; maxilla short, with one tooth; maxillae rotates so that fangs folded during feeding distinguishes from Elapids); venom teeth are closed tubes (solenoglyph) without visible seam; quadrates flared outward and highly mobile skull; venom common. Largely ambush predators of mammals, injecting venom, then following scent trail.
Image:Agkistrodon contortrix laticinctus from Viperidae.
Links: Encyclopedia Entry; Viperidae; Animal Diversity Web: Family- Viperidae; Squamata/VIPERIDAE/viperidae01.html">Reptilia, Squamata, Ophidia, Viperidae - Vipern German); Viperidae.html just pictures); Viperidae Familyasi Turkish); I Viperidi, Viperidae Italian: very thorough coverage); Viperidae Mikko). ATW030121.
Azemiopinae: (= Azemophinae): Azemiops (Fea's viper).
Range: R of China, Tibet, northern parts of SE Asia.
Characters: <82 cm long; head somewhat flattened & slightly triangular; fangs short; venom sacs comparatively small; loreal infra-red sensitive) pit-organs absent; moderately sturdy body, with short tail; no tracheal lung; head with with large plates (colubridlike head scales); head scales orange; smooth body scales, body has widely spaced orange rings on a background of deep blue-gray to black; feeds on small mammals and lizards; vibrates tail against vegetation when threatened; hibernates in winter; oviparous.
Image:Azemiops from Viperidae.
Links: Viperidae; NCBI; ??? - ???? Azemiops feae Chinese). ATW030503.
Viperinae: Adenorhinos, Atheris, Bitis, Cerastes, Daboia, Echis, Macrovipera, Vipera. "Pitless vipers."
Links:Viperinae; Viperidae; Viperinae2001; The World Of Atheris; Biochem. J. - Bile acids of Viperinae; Viper's; Snake Basics 2 - Simon's Snake Website. ATW020817.