Nature & Environment

Prehistoric Bird Diatryma Was Herbivore, Scientists Say

Sandra Smith
First Posted: Nov 23, 2012 03:42 AM EST

Diatryma, the giant bird which was once depicted as a carnivorous predator, was actually a herbivore, researchers say. A recent analysis of the footprints of the huge bird showed that its toe-like claws lacked the talons needed to hunt prey.

A team of researchers from Western Washington University (WWU) uncovered a fossilized footprint of a prehistoric Diatryma in 2009, while they were examining a landslide near the Chuckanut Formation in northwest Washington.

The flightless bird, which measured up to seven feet and weighed around 380 pounds, lived in the Pacific Northwest during the Eocene epoch some 56 million years ago. The giant bird had a huge head and a strong beak. It was earlier illustrated as a fierce carnivore that fed on small mammals including small ancestors of horses.

But recent analysis of the bird's footprints made 55.8 to 48.6 million years ago in the Lower Eocene suggests that the bird was a herbivore and not a carnivorous predator. The research team noticed that the bird's prints lack raptor-like claws, which suggests that the Diatryma was not a meat-eater.

Further analysis of the tracks showed that the bird had only small stubby triangular claws and did not possess long grasping talons found in all carnivorous birds, a report in BBC said.

"[The tracks] clearly show that the animals did not have long talons, but rather short toenails," David Tucker, from WWU, who worked on the study, told BBC.

"This argues against an animal that catches prey and uses claws to hold it down. Carnivorous birds all have sharp, long talons," he said.

Experts also suggested that Diatryma had smaller legs, which would hamper the flightless birds in running fast and capturing prey.

Although the bird acquired a strong beak, it did not have a hook on its end needed to hold on to the prey. Instead, researchers believe that Diatryma used its strong beak to crush leaves and collect fruits and seeds.

The findings of the study, "Giant Eocene bird footprints from Northwest Washington, USA," are published in the journal Paleontology.

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