Diatryma gigantea

Geologic Time: 55 million years ago (Early Eocene)

Geographic Range: Wyoming, New Mexico, Colorado, New Jersey, Canada's Ellesmere Island, France, Germany

Adult Size: Total Height - 7 ft. (2.14 m); Skull Length - 1.5 ft. (0.5 m); Weight - 385 lbs. (170 kg)

Habitat: Lowland Floodplains

Diet: Meat or possibly vegetation.

Diatryma was first discovered in Wyoming by Edward Drinker Cope in 1876. The Greek name Diatryma, which literally means "through a hole," was deduced for this bird because of its large foramina (perforations) that penetrate some of the foot bones. After the extinction of the dinosaurs, large ground-dwelling carnivorous birds, such as Diatryma, filled in the role left vacant by the flesh-eating theropod dinosaurs. The gigantic head, short powerful neck, and functionless forelimbs of Diatryma are all reminiscent of a small Tyrannosaurus rex, which suggests that it had a similar lifestyle and diet. Most paleontologists agree that Diatryma was a fierce carnivore preying on the contemporary mammals, especially young, sick and old individuals. Others however disagree and argue that it was a browsing herbivore, grazing on coarse vegetation and using its large bill as a scythe. The Willwood Formation in northeastern Wyoming is home to the most productive fossil assemblage of Diatryma remains in the world.