Dinosaurs Led to Rapid Rise of Birds

If you're trying to find the "missing link" between dinosaurs and birds, you're going to come up empty. New research has found that dinosaurs, massive prehistoric meat-eaters, rapidly gave rise to the thousands of bird species that we see today.

Birds are defined by a plethora of familiar traits such as feathers, wings and wishbones. Paleontologists once supposed that the earliest bird, 150-million-year-old Archaeopteryx, represented a great evolutionary leap from dinosaurs, according to National Geographic. But the new study paints a completely different picture.

As described in the journal Current Biology, birds evolved from dinos in a piecemeal fashion over tens of millions of years before finally taking flight in a burst of feathered diversity.

"There was no moment in time when a dinosaur became a bird, and there is no single missing link between them," lead author Steve Brusatte, of the University of Edinburgh's School of GeoSciences, said in a statement. "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."

Brusatte and his colleagues looked at a database of 150 extinct dinosaur species that led to both Tyrannosaurus rex and birds. This allowed them to compare more than 850 body features from the fossils, from the presence or absence of feathers to the size of the gap between their wrist bones. Based on their findings, they discovered that many avian traits had evolved in dinosaurs long before Archaeopteryx came into the picture.

The emergence of birds some 150 million years ago was a gradual process, making it difficult to draw a dividing line on the family tree between dinosaurs and birds.

"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," explained researcher Steve C. Wang.

The findings support a controversial theory that the emergence of new body shapes and features in groups of species could result in a surge in their evolution.