Family Tree Reveals How Birds Evolved from Predatory Dinosaurs

Scientists have taken a look at the most comprehensive family tree of meat-eating dinosaurs to date. Now, they're using this family tree to uncover key details of how birds evolved from these prehistoric terrors, examining feathers, wings and wishbones.

Fossil records show that birds emerged about 150 million years ago. Yet their appearance was a gradual process, as some dinosaurs became more bird-like over time. This means that creating a dividing line on the family tree between birds and dinosaurs can be somewhat difficult. This new family tree, though, seems to indicate that the emergence of new body shapes in groups of species could result in a surge in their evolution.

"The evolution of birds from their dinosaur ancestors was a landmark in the history of life," said Steve Wang, one of the researchers, in a news release. "This process was so gradual that if you traveled back in time to the Jurassic, you'd find that the earliest birds looked indistinguishable from many other dinosaurs."

The scientists took new kinds of data from the fossil record which hinted that early birds had a high rate of evolution. While birds evolved over millions of years, accumulating small shifts in shape and function of the skeleton, once all of these pieces were in place they evolved rapidly.

"There was no moment in time when a dinosaur became a bird, and there is no single missing link between them," said Steve Brusatee, lead researcher of the new study. "What we think of as the classic bird skeleton was pieced together gradually over tens of millions of years. Once it came together fully, it unlocked great evolutionary potential that allowed birds to evolve at a super-charged rate."

The findings reveal a bit more about both bird and dinosaur evolution. Not only that, but it shows how birds' ancient ancestors made the first changes in their path toward modernity.

The findings are published in the journal Current Biology.