Differences in modern birds
Modern birds evolved shorter upper arm bones and specialized tertial feathers to close this gap.
Remarkably, the Chicago specimen of Archaeopteryx shows it had long tertial feathers too – something unseen in its flightless dinosaur relatives.
“Our specimen is the first Archaeopteryx that was preserved and prepared in such a way that we can see its long tertial feathers,” she noted.
These feathers, absent in closely related non-avian dinosaurs, suggest those creatures couldn’t fly.
“That tells us… Archaeopteryx could,” O’Connor added. “This also adds to evidence that suggests dinosaurs evolved flight more than once – which I think is super exciting.”