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
|
|
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| Anomalepididae
|
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| Typhlopidae
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Alethinophidia |
| Anilius
|
|
Core Alethinophidia |
Uropeltidae | |
|
Macrostomata |
Pythonidae |
| Pythoninae
|
|
| Xenopeltis
|
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| Loxocemus
|
|
|
|
Caenophidia |
| Colubridae
|
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| Acrochordidae
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| Atractaspididae
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| Elapidae
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| Hydrophiidae
|
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| Viperidae
|
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|
Boidae |
| Erycinae
|
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| Boinae
|
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| Calabaria
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| Ungaliophiinae
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| Tropidophiinae
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Note: the tree only indicates relationships, not evolutionary branching times.[6]
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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]
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