Dr. Federico Degrange from the Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET, and the Universidad Nacional de Córdoba, Argentina and colleagues have found the most complete phorusracid fossil ever discovered. The phorusracids are commonly called “terror birds” and were the top predators in South America between 62 million years ago and 2.5 million years ago.
The new species of terror bird is named called Llallawavis scagliai (“Scaglia’s Magnificent Bird.” The animal was four feet tall and lived in what is now known as Argentina 3.5 million years ago. This fossil is the most complete phorusracid ever found. The researchers estimate that at least 90 percent of the animal was extracted in the fossil.
The remains include bones that helped focus the eye, a complete trachea, and a complete set of bones involved in hearing. The new fossil explains some of the sensory capabilities of this species of phorusracid and may explain the sensory characteristics of all the terror birds. The birds did not see as well as modern birds. Llallawavis scagliai heard sounds in the lower auditory range. This indicates that hearing was a major sense for hunting and was involved in finding mates.
All phorusracids could not fly. The animals are true birds. The largest of the group was almost 10 feet tall and probably could reach speeds of 30 miles an hour in short bursts. The beak of the birds was the major killing weapon for prey animals. Fossils of 16 distinct species of terror birds have been found. This find is the seventeenth and most complete of them all.
