Ornithosuchus

Description
Ornithosuchus (meaning "bird crocodile") is an extinct genus of crurotarsan from the Late Triassic of Scotland. Originally it was thought to be the ancestor to the carnosaur dinosaurs (which then included Tyrannosaurus), however now it is known to be more closely related to crocodilians than dinosaurs.

Despite this relationship to crocodiles, Ornithosuchus was able to walk on its hind legs, like may dinosaurs. However, it probably spent most of its time on all fours, only moving bipedally when it needed to run rapidly. Its skull also resembled those of theropod dinosaurs, but more primitive features included the presence of five toes on each foot and a double row of armoured plates along the animal's back. Ornithosuchus was around 4 meters (13 ft) in length.

Classification and taxonomy
A single species of Ornithosuchus has been described, the type species, O. longidens. Ornithosuchus is the type genus of the Ornithosuchidae, a family of facultatively biped carnivores that were geographically widespread during the Late Triassic. Two other genera are currently known, Venaticosuchus and Riojasuchus.