A remarkable fossil site in northwest China has uncovered the remains of hundreds of prehistoric birds, including chunks of broken bone compressed into pellet-like masses similar to those produced by modern owls. Paleontologists have long suspected that large predators played a role in hunting these birds, but no direct evidence of such animals had ever been found.
Now, a newly described dinosaur may provide the answer.
In a study published in Carnegie Chronicle MuseumResearchers report that a previously unknown dinosaur species was discovered in the same fossil bed. the animal was a feathered relative Velociraptor Both the front and hind legs have long feathers. Based on the unique characteristics of the arm and shoulder bones, scientists believe this dinosaur may have been the predator responsible for the mysterious bird bone accumulation.
“Scientists found these strange, dismembered chunks of bird bone at this site, but we didn’t know what made them. This new Microraptor dinosaur, Jian chanmensis, is our best guess,” says Jingmai O’Connor, associate curator of fossil reptiles at Chicago’s Field Museum and lead author of the paper describing the new species. “It was the only dinosaur found at this site that was not a bird, but a carnivore, and it was much larger than other dinosaurs found here.”
Velociraptor’s feathered relatives
Modern birds are the only dinosaurs to survive the aftermath of an asteroid impact on Earth 66 million years ago. But long before that event, from the Jurassic to the Cretaceous period, birds coexisted with many other dinosaur groups.
Among its closest relatives are the dromaeosaurs, a group of feathered dinosaurs known for being relatively small and agile predators. Velociraptorbecame famous by jurassic park In the movies, they are one of the most famous members of the group (although they would have been smaller and had feathers than depicted in the movies).
The newly identified species is Jiang Changmensisbelongs to a subgroup of dromaeosaurs called Microraptors. Most Microraptors were very small, with some species only as large as a crow.
“Jian is one of the largest Microraptor specimens ever discovered,” O’Connor said. “The part of the humerus bone that we have is about 4 inches long, so the overall wingspan of this dinosaur was probably about 4 feet, making it about the size of a barn owl.”
4 winged gliding dinosaur
Scientists have only recovered part of the animal’s arm, but Jean It shared important characteristics with other Microraptors. Long feathers probably cover both the arms and legs, giving the appearance of four wings.
These dinosaurs probably were adapted to glide, rather than fly like modern birds.
“Jian and the other Microraptors probably weren’t capable of truly powered flight, but they probably could glide like a flying squirrel,” O’Connor said.
A dinosaur’s name reflects both its appearance and where it was found. In Chinese mythology, a jian is a winged creature. chanmensis This refers to the Changma Basin in Gansu Province, China, where the fossil was discovered.
New insights into the early bird ecosystem
Researchers say the discovery fills an important gap in the ancient ecosystem represented by the Chamma fossil site.
“Jiang Changmensis reveals that non-avian dinosaurs lived in the modern-day Changma Basin, famous for its bird fossils,” said Matt Lamanna, corresponding author of the study and senior dinosaur researcher and Mary R. Dawson Curator of Vertebrate Paleontology at the Carnegie Museum of Natural History. “Our team has recovered more than 100 bird fossils at Changma, but this is the only non-avian dinosaur specimen. Jiang provides important new insights into the biological history of the Changma region and the ecological background of the ancestors of today’s birds.”
The discovery will also help scientists better understand how birds evolved and what makes their lineage different from their dinosaur relatives.
“You can’t understand life on Earth today without looking at its origins,” O’Connor says. “Birds are perhaps the most successful group of land-dwelling vertebrates on Earth today. By learning about early birds and their non-avian dinosaur relatives, we can better understand what made this surviving group of birds so special.”
Contributing to this research were Ling-Qi Zhou (Gansu Provincial Museum of Geology), Matthew Lamanna (Carnegie Museum of Natural History), Ashley Poust (University of Nebraska State Museum and University of California Museum of Paleontology), Da-Qing Li (Gansu Agricultural University), Hai-Lu You (Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences), and Jingmai. O’Connor (Field Museum).
