Bipedal trackways are the most common. They contain left-right sequences of similarly shaped prints, each containing three major digit marks. They are commonly called "three-toed tracks" or tridactyl tracks. Most bipedal dinosaurs actually possessed four digits on each foot, but one digit (the hallux) was small and held in an elevated position at the inside rear of the foot. When recorded at all, hallux marks are usually small and shallow.