A decade-long study revealed that a relative of the modern day ostrich, kiwis and tinamous once roamed North America.

About 10 years ago, a completely intact fossil was found in a former lake bed in the Green River Formation in Wyoming. Because the hollow and soft bird bones are more likely to be crushed during fossilization, the discovery of the fossil in Wyoming was labeled rare and exceptional.

Sterling Nesbitt, an assistant professor in the Department of Geosciences at Virginia Tech who discovered the fossil, revealed that it belongs to a 50-million-year-old species that have not been discovered before.

"This spectacular specimen could be a 'keystone' that helps interpret much of the sparse fossil of birds that once lived in North America millions of years ago," Nesbitt, said in a news release.

The release describes the former lake where the fossil was unearthed as a location "best known for producing scores of complete fish skeleton fossils as well as other fossils," including other birds, turtles, and mammals from an ecosystem estimated to be 50 million years old.

The species was named Calciavis grandei: calci which translates to "hard/stone," avis which is Latin for bird, and grandei which was inspired by the famed paleontologist Lance Grande.

The species was described by IFL science as a bird about the size of a chicken. The article added that it most dwelled on land and is almost flightless.

Calciavis grandei belongs to the extinct group of early Palaeognathae birds, the Lithornithidae, among one of the earliest well-represented bird species after the age of large dinosaurs.

The researchers believed the species used to live in the then forested environment of Wyoming and reached their extinction status when forests disappeared, leaving the place hot and dry.

Researchers described the new species in the Bulletin of the American Museum of Natural History.