This is the largest of all Eocene birds, Gastornis, a half-pile of muscle and feather as tall as a grown man.
— Allen, about Gastornis

Gastornis (name meaning "Gaston's Bird"), also known as Diatryma, is an extinct genus of large, prehistoric, flightless predatory died that originated during the Paleocene and the Early Eocene epoch in what is now Germany, France, and North America. It was smaller but more robust than the terror bird.

Strangely, it's been questioned whether this animal was a herbivore or a carnivore or even an omnivore. Nonetheless, Gastornis was the apex predator for the Paleocene and much of the Eocene that ruled over the plethora of small animals that had survived the K-T Extinction of the dinosaurs 65 MYA, dying out only when larger mammalian predators such as Hyaenodon evolved.


Era & DiscoveryEdit

Gastornis lived during the Early Eocene period, over 50 million years ago. It was the apex predator of its time. Gastornis was first described in 1855 from a fragmentary skeleton. It was named after Gaston Planté, described as a "studious young man full of zeal", who had discovered the first fossils in Argile Plastique formation deposits at Meudon near Paris.

Physical AttributesEdit

The largest of all predatory Eocene birds, Gastornis stood about 6 feet tall, as tall as a grown human, and weighed 1000 lbs., making them the second largest flightless bird ever to exist, after the Terror Birds Phorusrhacos.

Behavior & TraitsEdit

1000px-WWB1x1 GastornisCheckingEgg

Female Gastornis with an egg

Gastornias were solitary creatures, only getting together during mating season. When female Gastornias laid eggs, the had to wait two months for them to hatch. These birds were also fiercely territorial and when another Gastornias (whether it be male or female) got to close, the mothers moved to protect their nest.

Since the great extinction of the dinosaurs, birds like Gastornis had been a success like all mammals but, what was more, they grew large – enough so to take over the role of the predatory dinosaurs, from as small as the lethal Velociraptors to as giant as even the terrifying Tyrannosaurus rex.