Brontosaurus
"Brontosaurus" was a large, long-necked quadrupedal animal with a long, whip-like tail, and forelimbs that were slightly shorter than its hindlimbs. The largest species, "B. excelsus", weighed up to and measured up to long from head to tail. For comparison, the current largest land animal, the average male African bush elephant is 3.20 m (10.5 ft) tall at the shoulder and has a body mass of 6,000 kg (13,228 lb) or 6.6 short tons.
Dilophosaurus
"Dilophosaurus" was one of the earliest large predatory dinosaurs, a medium-sized theropod, though small compared to some of the later theropods. Slender and lightly built, its size was comparable to that of a brown bear. The largest known specimen weighed about , measured about in length, and its skull was long. The smaller holotype specimen weighed about , was long, with a hip height of about , and its skull was long. A resting trace of a theropod similar to "Dilophosaurus" and "Liliensternus" has been interpreted by some researchers as showing impressions of feathers around the belly and feet, similar to down. Other researchers instead interpret these impressions as sedimentological artifacts created as the dinosaur moved, though this interpretation does not rule out that the track-maker could have borne feathers.