(ORDO NEWS) — In the northwestern part of China, paleontologists have found fossils of an unusual species of ancient birds.
They had a toothy beak with a previously unseen feature: its lower half could move from side to side. The description of the find was published by the Journal of Systematics and Evolution.
“We assume that the movable part of the lower jaw of these birds was needed to capture food or feel prey,” said Jingmai O’Connor, one of the authors of the article, curator of the Fields Museum in Chicago (USA).
Over the past 20 years, ideas about what dinosaurs and the first birds looked like and how they evolved have changed radically.
Now scientists believe that almost all dinosaurs had plumage, many of them hatched eggs and cared for offspring. Several species of ancient protobirds, such as Gansus yumenensis and Confuciusornis sanctus, now claim the role of the “lost link” of evolution.
During excavations in northwestern China at the Changma site, O’Connor and his colleagues found fossils of two more Mesozoic birds.
There are rocks formed at the beginning of the Cretaceous period, approximately 125-113 million years ago. It was in such rocks that scientists found the first fossils of Gansus yumenensis and other species of first birds.
Bird with movable beak
Recently, scientists have found a layer of rocks in this region with the imprints of the bones of several hundred ancient birds. Most of them belonged to the species Gansus yumenensis or its closest relatives, but there were also traces of previously unknown species, which scientists named Meemannavis ductrix and Brevidentavis zhangi.
Meemannavis ductrix was similar to Gansus yumenensis and modern birds. It was named after Zhang Miman, the first woman to head the Beijing Institute of Paleoanthropology and Invertebrate Paleontology.
The second species was distinguished by a bizarre anatomy of the beak and jaws, not characteristic of all other birds of the Cretaceous period.
As paleontologists have found out, Brevidentavis zhangi had an unusually short, toothy beak. Paleontologists believe that the bird could move its lower part from side to side.
This conclusion is based on the fact that the lower jaw of these birds was equipped with the so-called predentary bone, analogues of which allowed some ornithischian dinosaurs to move the horny beak to the sides when chewing food.
Scientists suggest that this unusual feature of the anatomy helped the birds search for food in the soil or in the soil at the bottom of rivers and lakes. In favor of this, in particular, is evidenced by the fact that there were many nerve endings in the predentary bone, which helped the birds to “feel” invisible prey.
Subsequent excavations and the discovery of more complete body prints of these birds, as O’Connor and his colleagues hope, will allow scientists to clarify the place of these birds in Cretaceous ecosystems.
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