The Changma River basin in northwestern China's Gansu province is known for its numerous ancient bird fossils. Or at least, fragments Fossils. Paleontologists have documented over 100 remains of prehistoric bird-dinosaurs buried in this region, many of which resemble the digestive boluses regurgitated by modern owls. For years, researchers suspected that a similar predator was responsible for these fossil fragments, but a convincing candidate was never found.
Experts have a plausible suspect, according to a study published today in the journal Annals of the Carnegie Museum , a relative of the terrible velociraptor lived in the Changma River basin about 120 million years ago. But with its long feathers and four "wings"« Jian changmaensis It didn't ambush its prey from a great height, like a falcon. Rather, it swooped down like a flying squirrel.
«"This is the only dinosaur found at this site that was not a bird, but a predator, and it was much larger than all the others we've found there," Jingmai O'Connor, co-author of the study and associate curator of fossil reptiles at the Field Museum, said in a statement.
Paleontologists have proposed a theory about the dinosaur's anatomy based on a fossil of its upper arm. Source: O'Connor et al.
Named after a winged mythological creature from Chinese folklore, J. changmaensis belongs to a subgroup of dinosaurs known as microraptors. These feathered predators were fast and small, often only the size of a crow. However, J. changmaensis It was comparatively large. Although O'Connor's team has only recovered part of its upper limb so far, they estimate that the dinosaur's wingspan was likely around four feet. This is roughly the size of a barn owl.
Although J. changmaensis Although it was larger than its Microraptor relatives, paleontologists believe it was physically similar to its relatives. This means the dinosaur likely had both wings on its forelimbs and vestigial "wings" on its hind legs. Microraptors couldn't glide, but their feathers served a purpose.
«"Likely, Jian "And other microraptors weren't capable of true powered flight, but they could probably glide like flying squirrels," O'Connor explained.
Matt Lamanna, a co-author of the study and curator of vertebrate paleontology at the Carnegie Museum, said the team's discovery provides "critically important new insights" into the biological history of the Changma region and helps contextualize modern-day bird-dinosaur descendants.
«"For decades, the Changma site has been known to paleontologists for its extraordinary bird fossils," Lamanna added. "Now, with the discovery Jian , we finally know who was feeding on them.".