a new study involving scientists from the University of Southampton has revealed how massive, meat-eating, ground-dwelling dinosaurs evolved into agile flying birds: they just kept shrinking and shrinking, for over 50 million years. Today, in the journal Science, the researchers present a detailed family tree of dinosaurs and their bird descendants, which maps out this unlikely transformation.
They showed that the branch of theropod dinosaurs, which gave rise to modern birds, were the only dinosaurs that kept getting inexorably smaller.
"These bird ancestors also evolved new adaptations, such as feathers, wishbones and wings, four times faster than other dinosaurs," says co-author Darren Naish, Vertebrate Palaeontologist at the University of Southampton.