If true, the results suggest that human sleep patterns evolved by around 300 million years ago in a common ancestor of birds, mammals and reptiles. (sciencenews.org)
A common ancestor of birds and mammals may have had a membrane for protecting the eye and sweeping out debris. (discovermagazine.com)
THE DESCENT OF BIRDS Dinosaur ancestors of birds shrank steadily for more than 50 million years. (sciencenews.org)