Origin of birds
"Analysing 24 specimens, the researchers identified 17 species, seven of which were 'archaic birds' that are not seen after the K-T mass extinction. These findings show for the first time a diversity of archaic birds alive, right up until the end of the Cretaceous. This would mean that the archaic birds went extinct abruptly 65 million years ago, and that modern birds must have descended from just a few groups that survived the event".