Chicken-Sized Ostrich Relative Roamed N. America

Calciavis, a new species and early relative of ostriches, stands by the shores of an Eocene lake.

Picture a modern-day ostrich – the world's largest bird, anywhere from around 6 to nearly 9 feet tall -- and then shrink it down to the size of a chicken. That's what you get if it's Calciavis grandei you're picturing: a 50-million-year-old, newly documented bird species and an early relative of the ostrich we know and run from today.

Fossils of the bird were found 10 years ago in Wyoming's Green River Formation, an area that's considered a bonanza for extinct fish fossils as well as other long-dead creatures such as crocodiles, bats and turtles.

After long examination of the fossils, the new species has been documented in a study in the Bulletin of the American Museum of Natural History by researchers from Virginia Tech and the University of Texas.

The authors of the research consider the fossils singular finds for paleontologists.

"This is among one of the earliest well-represented bird species after the age of large dinosaurs," said study co-author Sterling Nesbitt, of Virginia Tech, in a statement. Nesbitt has been studying the fossils since 2009.

In all, two fossils of the species were found, one of which a near-complete skeleton, with soft-tissue remains, covered in feather remnants. They date from the Eocene epoch, some 30 to 56 million years ago.

Shown is a nearly complete skeleton of Calciavis grandei, a close relative of ostriches, kiwis, and emus.

The scientists say the ancient bird would have been about the size of a chicken and would have lived primarily on the ground, flying only for short bursts in the "Wyoming" of its day -- a much different place at the time.

"Back whenCalciavis was alive," Nesbitt said, "it lived in a tropical environment that was rich with tropical life, and this is in stark contrast to the high-desert environment in Wyoming today."

Read more at Discovery News