Largest genus of snakes

Boasting 143 species (as of 8 February 2020), the largest snake genus is Atractus – commonly known as the arrow groundsnakes. Their range is largely restricted to South America, just edging into Central America, occurring from Panama to Argentina. The majority of these vermivorous (worm-eating) snakes are fairly small, with a few exceptions; for example, A. gigas and A. touzeti have been documented growing to 1.2 metres (3 feet 11 inches) in length. At the other end of the scale, one of the smallest species is A. charitoae, reaching just 15.5 centimetres (6.1 inches) in total body length.

Atractus may only be one of 533 snake genera, but it accounts for 3.88% of all living snake species. This single genus contains more species than do 26 of the 33 snake families.

The largest five genera (below) contain 436 species and account for 11.53% of all snakes.

1. Atractus (South American arrow groundsnakes) Dipsadidae, Dipsadinae: 147 spp.

2. Oligodon (Asian kukri snakes) Colubrinae, Colubrinae: 79 spp.

3. Micrurus (American coralsnakes) Elapidae, Elapinae: 81 spp.

4. Tantilla (American black-headed centipede snakes) Colubridae, Colubrinae: 66 spp.

5. Calamaria (Asian reedsnakes) Colubridae, Calamarinae: 63 spp.