The Querètaro Dusky Rattlesnake ("Crotalus Aquilus") also known as the "Vibora de cascabel", is a species of venomous Pit viper found usually on highlands of central Mexico. The scientific name ""Aquilus"" is a Latin word meaning "eagle", referring to the highlands on which it lives on. They are not a very well known species of rattlesnake, but the people in Mexico know much about them.