A 12-million-year-old fossil in South America may belong to the largest terror bird ever found.
The giant bird’s lower femur was found by a museum curator in Colombia’s fossil-rich Tatacoa desert 20 years ago, but experts didn’t realize it belonged to a terror bird until 2023. This year, researchers created a 3D model of the specimen, using a portable scanner, allowing them to analyze the fossil more closely. “We are talking about a species that is more than 2.5 meters tall and weighs more than 150 kilograms,” Newsweek on November 4 quoted research author Federico Javier Degrange at the Earth Science Research Center in Argentina.
The Phorusrhacid, commonly known as the “terror bird,” belongs to an extinct family of medium-sized to extremely large raptors. They were apex predators for a long time in the Cenozoic Era 66 million years ago. This bird is mainly found in southern South America, has an elongated body and is uniquely adapted for running on the ground. Their oversized beak and skull structure suggest they were effective predators. According to Siobhán Cooke, associate professor of functional and evolutionary anatomy at Johns Hopkins University School of Medicine, terror birds live on the ground, have limbs adapted for running, and primarily eat other animals.
In an article published in the journal Papers in Palaeontology, the research team identified the fossil bone as the first evidence of a large terror bird from the mid-Mesozoic (about 11.6 – 16 million years ago) in Fossil mines in central Colombia. Although the specimen only included a piece of lower femur called the left tibia, its size led researchers to speculate that it was one of the largest terror birds to have ever existed, possibly weighing more than 154 kg. This fossil is the most northern evidence of a terror bird in South Africa to date.
The research team estimates the animal is 5 – 20% larger than known terror birds, 1 – 3 m tall based on previously discovered fossils. However, limited genetic material prevented them from determining which genus the new species belonged to. What’s special is that the fossil with tooth marks most likely belongs to an extinct species of crocodile named Purussaurus that could be more than 9 m long. Therefore, experts suspect that the terrorist bird died from injuries caused by a crocodile.