Some early predatory birds and feathered dinosaurs had multiple wings on both their arms and legs. These creatures were known as microraptoria, or Microraptor. One of the largest of these multiple winged creatures was known as Sinornithosaurus, which was suspected to be venomous by certain grooves running down the outer surface, towards the rear of the tooth, a feature seen only in venomous animals, such as snakes and the venomous Gila Monster lizard. North American folklore also speaks of multiple winged creatures with venomous fangs and talons.