"We estimate that having a long tail increases a bird's daily metabolic costs by 1 to 3 percent, which means the bird has to visit 1 to 3 percent more flowers in its territory," said Christopher J.

It had feathers and wings, so it was clearly a bird — but it sported a long tail and sharp claws, which seemed reptilian. A smattering of other feathery Jurassic fossils, including those known ...