File photo: Chinsamy-Turan said these dinosaurs were known as 'four-winged' dinosaurs because the long feathers attached to the legs looked like a second set of wings.

Cape Town - Long ago somewhere in China lived dinosaurs covered in feathers. There were also smaller, flying dinosaurs.

The bigger, feathered dinosaurs were not enormous – about 2m long – and despite their feathers they could not fly. But they were stealthy predators - stealthy enough to creep up on smaller, flying dinosaurs and catch them in midflight.

This may sound like something from a fantasy movie, but researchers from the University of Alberta have found evidence of these creatures and their diet from fossil remains uncovered in northeast China. The remains are between 100 to 145 million years old.

The research, published in the journal PLoS One this week, described the find as rare.

The bigger dinosaur was a predator called Sinocalliopteryx. Its “flying meals” were called Confuciusornis.

These were some of the earliest birds and had a crude version of a modern bird’s skeleton. Researchers say they were probably not able to fly as well as modern birds, but were slow to take off and managed short flights only. They were about the size of a domestic cat and were meat-eaters.

How they discovered that the larger dinosaur dined off the smaller one was because the creature’s last meal had become fossilised inside its stomach cavity.

Researchers found the remains of not just one flying dinosaur in its belly, but three of them.

According to a press statement issued by EurekAlert!, research co-ordinator Scott Persons of the University of Alberta said the fact that the creature had three undigested birds in its stomach indicated that it was “a voracious eater and a very active hunter”.

They say this is the first time a predator has been linked to the killing of multiple, flying dinosaurs.

“What is required to apprehend avian prey successfully is not climbing skills but stealth, so that the predator can reach its striking distance before the prey take flight,” researchers said in the paper.

The fossil evidence of these early birds in the dinosaur’s stomach was clear evidence that Sinocalliopteryx was a “highly capable stealth hunter”. - Cape Times