Spectacular prehistoric birds unearthed near Great Wall of China

By Mark Waghorn via SWNS

A lost world of spectacular prehistoric birds has been unearthed near the Great Wall of China.

The fossilized bones shed fresh light on the evolution of our feathered friends.

One newly discovered species had small, closely packed peg-like teeth - and a moveable pincer-like 'chin.'

It has been called Brevidentavis zhangi - which translates as 'short toothed bird.'

Another, called Meemannavis ductrix, was toothless - like its modern descendants.

The treasure trove was discovered at an ancient graveyard at Changma - 80 miles from the wall's westernmost reach.

It includes more than 100 specimens of creatures that lived 120 million years ago during the time of the dinosaurs.

An international team analyzed skulls and necks from six - and identified the flexible bony appendage at the tip of Brevidentavis' lower jaw.

The adornment, known as a predentary, was also highly sensitive - suggesting the bird used it to hunt prey.

Lead author Professor Jingmai O'Connor, curator of vertebrate paleontology at Chicago's Field Museum, explained: "Brevidentavis is an ornithuromorph bird with teeth.

"In ornithuromorphs with teeth, there is a little bone at the front of the jaw called the predentary, where its chin would be if birds had chins."

Previous scans of another fossil bird showed it underwent stress - and identified cartilage that only forms when there is movement.

Prof O'Connor said: "In this earlier study, we were able to tell the predentary was capable of being moved, and that it would have been supplied with nerves.

"Brevidentavis wouldn't just have been able to move its predentary, it would have been able to feel through it. It could have helped them detect prey.

"We can hypothesize these toothed birds had little beaks with some kind of moveable pincer at the tip of their jaws in front of the teeth."

The discoveries add to our understanding of prehistoric bird diversity, especially in the Changma region - about 1,200 miles west of Beijing.

Other specimens examined belong to Gansus yumenensis - the oldest known member of the group that includes modern birds.

Co-author Prof Hai-Lu You, of the Chinese Academy of Sciences, Beijing, said: "Gansus is the first known true Mesozoic bird in the world, as Archaeopteryx is more dinosaur-like, and now we know what its skull looks like after about 40 years."

Archaeopteryx lived around 150 million years ago and has been dubbed the 'world's first bird.'

It is actually intermediate between the birds we see flying around in our gardens and predatory dinosaurs like Deinonychus.

The raven-sized creature had feathers on its legs and wings and could fly short distances - a bit like a pheasant.

Co-author Prof Tom Stidham, also from the Chinese Academy of Sciences, said: "These amazing fossils are like a lockpick allowing us to open the door to greater knowledge of the evolutionary history of the skull in close relatives of living birds.

"At a time when giant dinosaurs still roamed the land, these birds were the products of evolution experimenting with different lifestyles in the water, in the air, and on land, and with different diets as we can see in some species having or lacking teeth.

"Very few fossils of this geological age provide the level of anatomical detail that we can see in these ancient bird skulls."

The study in the Journal of Systematics and Evolution is the culmination of excavations at the site in northwest China over the last two decades.

Many of these fossils are incomplete and badly crushed - making them difficult to classify.

Prof O'Connor said: "It was a long, painstaking process teasing out what these things were.

"But these new specimens include two new species that increase our knowledge of Cretaceous bird faunas.

"We found combinations of dental features that we have never seen in any other dinosaurs."

All birds are dinosaurs - but not all dinosaurs are birds. A small group evolved into birds. They coexisted for 90 million years.

Modern birds are the descendants of the group that survived the asteroid strike that wiped out the dinosaurs and many prehistoric birds.

Prof O'Connor's work focuses on studying different groups of early birds to figure out why some survived.

Co-author Prof Jerry Harris, of Utah Tech University, St George, said: "These fossils come from a site in China that has produced fossils of birds that are pretty darned close to modern birds.

"But all the bird fossils described thus far haven't had skulls preserved with the bodies.

"These new skull specimens help fill in that gap in our knowledge of the birds from this site and of bird evolution as a whole."

Changma is the second-richest fossil bird site from the age of the dinosaurs.

Most individuals are Gansus yumenensis - but their skulls and necks have never been found.

Co-author Dr. Matt Lamanna, of Pittsburgh's Carnegie Museum of Natural History, said: "The Changma site is a special place.

"The fossil-bearing rocks there tend to split into thin sheets along ancient bedding planes.

"So, when you are digging, it is like you are literally turning back the pages of history, layer by layer uncovering animals and plants that have not seen the light of day in roughly 120 million years."

Through painstaking work, the researchers were able to identify key features in the birds' jaws that showed two of the six specimens were unknown to science.

Prof O'Connor added: "Because the specimens were pretty flattened, CT-scanning them and fully segmenting them could take years and might not even give you that much information.

"These thin bones are flattened into almost the same plane. Then it just becomes almost impossible to figure out where the boundaries of these bones are. So we had to kind of work with what was exposed."