CBS: The fossil record holds evidence to support both scenarios, depending on which dinosaurs are being examined.
The researchers used data from over 3000 fossilized teeth from four different Maniraptora families to study variations in the teeth.
Scientists investigating this question have often looked at the diversity of dinosaurs leading up to 66 million years ago.
"There were bird-like dinosaurs with teeth up until the end of the Cretaceous, where they all died off very abruptly".
While...