Dinosaurs that made bipedal tracks fall into two major groups: theropods (bipedal meat-eating dinosaurs) and ornithopods (bipedal plant-eating dinosaurs). Theropod tracks typically exhibit relatively long and narrow digit impressions, terminated with sharp, slender claw marks. The posterior ends are typically somewhat V-shaped. Among theropods, a somewhat arbitrary division is made between small, gracile forms called coelurosaurs, and large, robust forms known as carnosaurs. Coelurosaur tracks often exhibit digits held closely together, and distinct toe pads. The shapes and positions of the pads are useful in identifying particular ichnogenera. The digit marks of carnosaur tracks are often more widely splayed and robust, with less distinct pads.