“Paleontologists got excited when we learned that birds are dinosaurs.”

An Ancient Step Toward Modern Birds. Anchiornis was a feathered dinosaur, about the size of a pigeon and incapable of flight. Its wings say a lot about how birds came to be.

Perhaps it was soft, even fuzzy. But it was also very much a dinosaur.

Anchiornis was a four-winged birdlike species that lived about 160 million years ago, and many fossil specimens have been found in China. A number of them were discovered with preserved feathers, but until recently the feathers had not been described in detail.

Anchiornis (the name means “near bird”) was about 14 inches long from its beak to the end of its tail, barely larger than a pigeon but much more impressive. It had long feathers on its four wings, and its appendages ended in claws.

Anchiornis did not, however, have the reverse toe of modern birds that allows them to perch. It climbed trees, hanging on with all four feet.

A recent study in Palaeontology takes a close look at its feathers. Anchiornis had small bushy plumes covering its back and neck, unlike its straighter wing and tail feathers.

The main function of these short feathers was to provide insulation, and they may have been water-repellent. But they were not as efficient at either of these tasks as the feathers of modern birds.

Anchiornis probably glided down from trees, like a flying squirrel, but likely was incapable of powered flight. The feathers on the wings and tail looked more like modern bird feathers, but lacked the curved aerodynamic structure that allows for flight.

“Paleontologists got excited when we learned that birds are dinosaurs,” said the lead author, Evan T. Saitta, a doctoral student at the University of Bristol in England. “But we have to remember that these things are much older and more primitive than birds. Feathers don’t evolve overnight. These are steppingstones on the way to modern birds.”