Etymology

Etymology

The English word snake comes from Old English snaca, itself from Proto-Germanic *snak-an- (cf. German Schnake "ring snake," Swedish snok "grass snake"), from Proto-Indo-European root *(s)nēg-o- "to crawl, creep," which also gave sneak as well as Sanskrit nāgá "snake."^[3] The word ousted adder, as adder went on to narrow in meaning, though in Old English næddre was the general word for snake.^[4] The other term, serpent, is from French, ultimately from Indo-European *serp- (to creep),^[5] which also gave Greek érpo (ερπω) "I crawl."

Evolution

A phylogenetic overview of the extant groups Modern snakes Scolecophidia Leptotyphlopidae   Anomalepididae Typhlopidae Alethinophidia Anilius Core Alethinophidia Uropeltidae Cylindrophis   Anomochilus Uropeltinae Macrostomata Pythonidae Pythoninae Xenopeltis Loxocemus Caenophidia Colubridae Acrochordidae Atractaspididae Elapidae Hydrophiidae Viperidae Boidae Erycinae Boinae Calabaria Ungaliophiinae Tropidophiinae Note: the tree only indicates relationships, not evolutionary branching times.[6]

The fossil record of snakes is relatively poor because snake skeletons are typically small and fragile, making fossilization uncommon. Fossils readily identifiable as snakes (though often retaining hind limbs) first appear in the fossil record during the Cretaceous period.^[7] The earliest known snake fossils come from sites in Utah and Algeria, represented by the genera Coniophis and Lapparentophis, respectively. These fossil sites have been tentatively dated to the Albian or Cenomanian age of the late Cretaceous, between 112 and 94 Ma ago. However, an even older age has been suggested for one of the Algerian sites, which may be as old as the Aptian, 125-112 Ma ago.^[8]