Scientists Uncover Fossil of a Terror Bird That Could Be the Largest Ever Known, Stood Over 8 Feet Tall

Scientists have found what could be the largest "terror bird" ever known, from a fossil in Colombia's Tatacoa Desert, according to the journal Papers in Palaeontology. This enormous predatory bird would have stood over eight feet tall and weighed about 344 pounds, dwarfing many of its South American relatives, having lived approximately 12 million years ago. The remarkable discovery was made from just one leg bone at the fossil site known as La Venta. Federico Javier Degrange, lead researcher from the National University of Córdoba in Argentina, identified the specimen as a possibly new species of the well-known terror birds, or phorusrhacids, when he studied several distinctive features in the bone structure unique to avian species.

These ancient birds were powerful predators that dominated the ecosystems of South America during the Miocene era. "They are the only group of birds that achieved the role of terrestrial apex predators, evolving species that basically conquered South America," Degrange told CNN. Most terror birds were considerably smaller, weighing on average between 11 and 220 pounds. The newly discovered specimen was taller than even its largest known relative, Paraphysornis brasiliensis from Brazil. Whereas P. brasiliensis stood nearly eight feet tall, the comparative weight came at 397 pounds against 344 pounds which was exhibited in the specimen obtained from La Venta.

The fossil has an exciting story all to itself. A curator at the Museo La Tormenta found the leg bone nearly twenty years ago, but it wasn't until Degrange examined it in 2023 that its significance was realized. His specialty in the anatomy of terror birds allowed him to instantly recognize the characteristics that marked it as a phorusrhacid. The La Venta discovery is particularly significant because it represents the northernmost terror bird fossil found in South America. Such findings suggest that these prehistoric predators could live in a range of habitats, from the temperate regions of Argentina to the tropical environments of Colombia. During the Miocene, La Venta was a swampy, forested, and grassland-rich landscape with plenty of potential prey, such as hoofed mammals.

The fossil also bears evidence of a dramatic encounter with another apex predator of the time. Deep marks into the bone show that it was attacked by a Purussaurus—a 30-foot-long giant caiman, according to Live Science. It is still a mystery whether this occurred during the life of the bird or after its death. This has raised new questions about the evolution of terror birds and their ability to grow to such incredible sizes remains under research. "We know that probably one of the drivers that led terror birds to get larger and larger was the competition between species of terror birds — but why that big?" wondered Degrange, who is fascinated by these prehistoric giants, as per CNN.