Colubridae

Colubridae (/kəˈluːbrɪdiː/, commonly known as colubrids /ˈkɒljʊbrɪdz/, from Latin coluber, snake) is a family of snakes. With 524 genera and approximately 1,760 species, it is the largest snake family, and includes just over 51% of all known living snake species. The earliest species of the family date back to the Oligocene epoch. Colubrid snakes are found on every continent except Antarctica. While most colubrids are not venomous (or have venom that is not known to be harmful to humans) and are mostly harmless, a few groups, such as genus Boiga, can produce medically significant bites, while the boomslang, the twig snakes, and the Asian genus Rhabdophis have caused human fatalities. Some colubrids are described as opisthoglyphous, meaning they have elongated, grooved teeth located in the back of their upper jaws, often called 'rear-fanged'. Opisthoglyphous dentition likely 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. 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, or Atractaspis. However, recent research in molecular phylogenetics has stabilized the classification of historically 'colubrid' snakes and the family as currently defined is a monophyletic clade, although additional research will be necessary to sort out all the relationships within this group. As of May 2018 eight subfamilies are recognized. Sibynophiinae – 11 species in two genera Natricinae – 237 species in 35 genera (sometimes given as family Natricidae) Pseudoxenodontinae – 10 species in two genera