210-Million-Year-Old Footprints Bring Birds, Dinosaurs Closer

More evidence that birds are descended from dinosaurs has been found in 210-million-year-old footprints of theropod dinosaurs found in Greenland, researchers from Brown University report in today’s Nature. The prints, left behind when the dinosaurs walked through mud of various consistencies, are remarkably similar to those left by modern-day birds such as turkeys, according to evolutionary biologist Stephen Gatesy.

The main differences they found were that dinosaur prints do not show imprints of the soles of the feet, while those of the birds do, indicating that their legs moved differently; and the big toes of birds point backward, allowing them to grasp objects and perch, while those of the dinosaurs do not.

Compiled by Times medical writer Thomas H. Maugh II