Gastornis

Gastornis is an extinct genus of large, flightless birds that lived during the late Paleocene and Eocene epochs, approximately 56 to 45 million years ago. Fossil evidence for Gastornis has been found in Europe, North America, and Asia, suggesting a wide geographic distribution. These birds were substantial in size, with estimates for the largest species reaching up to 3 meters (10 feet) in height and weighing hundreds of kilograms. They possessed powerful legs, a long neck, and a large, robust skull topped with a massive, hooked beak.

The exact diet and lifestyle of Gastornis have been a subject of debate among paleontologists. For many years, their large size and powerful beak led to the assumption that they were predators, capable of hunting large prey. However, more recent analyses of beak morphology and tooth wear patterns have suggested that Gastornis may have been herbivores, feeding on tough plant material. Alternative theories propose they might have been omnivores, incorporating both plants and smaller animals into their diet. Despite their imposing size, Gastornis lacked the ability to fly, a common trait among large terrestrial birds of that era. Their extinction is thought to be linked to environmental changes and competition with mammals that diversified and grew in size during the Eocene.