Allosaurids

Allosaurids are medium to large bipedal, carnivorous allosauroid theropod dinosaurs in the family Allosauridae from the Late Jurassic. Allosaurids are a fairly old taxonomic group, having been 1st named by the American paleontologist Othniel Charles Marsh in 1878. Allosaurids are characterized by an astragalus with a restriction of the ascending process to the lateral part of the bone, a larger medial than lateral condyle, and a horizontal groove across the face of the condyles.