Changyuraptor, four-winged Dinosaur had huge tail feathers, China.

Changyuraptor, a 125 million year old  four winged dinosaur with record breaking tail feathers from China.  Image Credit: Stephanie Abramowicz
Contributor: John Pickrell is the editor of Australian Geographic.
IN THE EARLY stages of evolving flight, feathered dinosaurs tried an interesting experiment: they developed four wings.
These small dinosaurs – such as Microraptor, Anchiornis and Xiaotingia – had large flight feathers on their hind limbs as well as their fore limbs, and they had long bony tails, similarly replete with large feathers.
It appears that many early birds, such as Archaeopteryx, may also have had long feathers on their hind limbs.
It was only later that birds developed the characteristically bald legs that (most) birds have today, and became aerodynamically stable on two wings and a much-reduced tail.
Microraptor was the first of the four-winged dinosaurs to be discovered, in 2003, and it was tiny for a dinosaur: approximately 1kg in weight and similar to a crow or a raven in size.
Miniaturisation, experts thought, was an essential step in developing flight.
But now a totally new four-winged dinosaur has been discovered, and it was much larger.
Changyuraptor yangi – described in the journal Nature Communications – would have been around 4kg in weight and about the size of a turkey.
It also has a really unusual feature: an incredibly long tail with 30cm feathers that trailed out behind the body.
These tail feathers were around 30 per cent of the length of the skeleton, making them the longest known feathers of any (non-bird) dinosaur.
Read further via New four-winged dinosaur has record-breaking tail feathers – Australian Geographic.