Crotalus enyo furvus
Crotalus enyo furvus, also known as the Rosario rattlesnake or the dusky Baja California rattlesnake, is a subspecies of Baja California rattlesnake, a kind of venomous pit viper. It is named after the Latin 'furvus' meaning 'dark complexion' or 'swarthy', referring to the colouration of the subspecies. It is found on the San Quentin Plain in Baja California del Norte - due to the area's restricted and largely inaccessible habitat not much is known about the subspecies.