The venom of the Guarico rattlesnake is almost entirely neurotoxic, similar to other subspecies of C. durissus. Little is known about this subspecies, and considerable debate exists on whether or not this snake even represents a unique subspecies, or simply an isolated "race" of C. d. cumanensis with smaller size and faded colors.

This small to medium-sized rattlesnake is endemic to Venezuela and does not occur anywhere else. It's habitat includes low-elevation forests, scrub, and savanna. The Guarico rattlesnake is often found in armadillo burrows.