Paleocene Index Page
Paleocene photograph scan of a drawing of Phororhacos longissimus, a giant prehistoric bird. This Paleocene photograph is by Charles R. Knight published in Animals of the Past, 1901.
Phorusrhacids (family Phorusrhacidae) or terror birds were large carnivorous flightless birds that were the dominant predators in South America, 62–2 million years ago.
The terror birds were roughly 1–3 meters (3–10 feet) tall. Their closest modern-day relatives are believed to be the seriemas. Titanis walleri, one of the larger species of terror bird, is known from North America, and is the only phorusrachid species known from outside of South America.
The ancestors of the terror bird T. walleri have not been found; however, it is possible that more North American species of terror birds await discovery.
Paleocene photograph of a reconstruction of the terror bird Diatryma.
The diatrymas terror birds were among the largest, if not the largest birds alive during the Paleogene. They had few natural enemies and serious competitors apart from other terror birds Gastornis or the few and then-rare large mammals, such as the predatory bear-like Arctocyon of Europe.
If these huge terror birds were active hunters, they must have been important apex predators that dominated the forest ecosystems of North America and Europe until the Middle Eocene.
