Dr. Thomas Tuetkin, from the University of Bonn in Germany, and his colleagues Dr. Meinolf Hellmund, Dr. Stephen Galer, and Petra Held presented new isotope analysis evidence at the Aug. 29, 2013 session of the Goldschmidt Conference in Florence, Italy that established the prehistoric bird Gastornis was a herbivore.
Gastornis was a flightless bird that lived between 40 and 55 million years ago. Fossils of Gastornis have been discovered in the United States and in Europe. The bird was almost seven feet tall and had a huge beak. The size of the beak led early paleontologists to conclude the bird was a predator and ate meat. The appearance and beak gave the name “terror bird” to Gastornis.
The researchers examined the calcium composition of a fossil Gastornis found in a coal mine in the Geiseltal, Germany. Calcium isotope composition indicates an animal’s major food source. The calcium isotope composition of bones is not changed by fossilization.
The fossil isotope analysis found Gastornis to be a plant eater. This information coupled with the fact that the bird had no teeth and recent Gastornis footprint evidence found in the United States that indicate the bird had no claws to grasp and hold prey with support the conclusion that the bird was a herbivore.