Fossil of Ancient Terror Bird Discovered in Argentina

Posted on May 24, 2015

Fossil of Terror bird, Llallawavis scagliai

Scientists have discovered the fossil of a previously unknown species of terror bird in Argentina. Terror birds (phorusracids) were carnivorous flightless birds that were fierce predators during the Cenozoic Age in South America. They were around 3 meters tall (10 feet) and had hooked beaks. The newly discovered species has been named Scaglia's Magnificent Bird (Llallawavis scagliai).

The fossil the researchers found is the the most complete terror bird fossil ever discovered. The scientists say that 90% of the skeleton has been exquisitely preserved. The fossil reveals details of terror bird anatomy that have not previously been observed, including a complete trachea and palate. The researchers told Live Science that the structure of the terror bird's inner ear indicates it could have heard the low rumbling of their prey's footsteps which would have given them an advantage when hunting.

Dr. Federico "Dino" Degrange, the lead author of the study from the CICTERRA, CONICET and the National University of Cordoba, says in a statement, "The mean hearing estimated for this terror bird was below the average for living birds. This seems to indicate that Llallawavis may have had a narrow, low vocalization frequency range, presumably used for intraspecific acoustic communication or prey detection"

The newly discovered terror bird was smaller than others. It was about 4 feet tall. It lived in Argentina about 3.5 million years ago. This was near the end of the reign of terror birds on Earth.

Dr. Claudia Tambussi, also of CICTERRA and one of the co-authors of the study, says, "The discovery of this new species provides new insights for studying the anatomy and phylogeny of phorusrhacids and a better understanding of this group's diversification."

A research paper on the new terror bird species was published here in the Journal of Vertebrate Paleontology.

Photo: M. Taglioretti and F. Scaglia.