is a specific kind of: reptile genus.

has as a member: banded rattlesnake, Crotalus horridus horridus, timber rattlesnake | Crotalus viridis, prairie rattler, prairie rattlesnake, Western rattlesnake | Crotalus cerastes, horned rattlesnake, sidewinder | Crotalus atrox, Western diamondback, Western diamondback rattlesnake | Crotalus lepidus, rock rattlesnake | Crotalus tigris, tiger rattlesnake | Crotalus scutulatus, Mojave rattlesnake | Crotalus mitchellii, speckled rattlesnake.

is a member of: Crotalidae, family Crotalidae.