NEW HAVEN, Conn., Sept. 19 (UPI) -- Prehistoric birds went extinct the same way dinosaurs did, U.S. researchers say, victims of the same meteorite impact 65 million years ago.
There has long been controversy about whether archaic birds, very different from today's species, died out slowly over time or were killed off by the giant impact in the Gulf of Mexico.
Researchers from Yale University say fossil evidence shows the birds were going strong right up until the time of the impact, and then mostly disappeared.
"This proves that these species went extinct very abruptly, in terms of geological time scales," Nicholas Longrich, a Yale paleontologist, said in a university release Monday.
The researchers examined a large collection of bird fossils discovered in North America representing a wide range of the species that existed during the Cretaceous period.
Longrich said he believes a small fraction of the archaic Cretaceous bird species survived the impact, and evolved into today's birds.
"The basic bird design was in place, but all of the specialized features developed after the mass extinction, when birds sort of re-evolved with all the diversity they display today," Longrich said. "It's similar to what happened with mammals after the age of the dinosaurs."