New Four-Winged Dinosaur Jian changmaensis Found in China

Paleontologists have unearthed a new species of non-avian dinosaur, named Jian changmaensis, in northwestern China. This discovery marks the first non-avian dinosaur found at a site previously known for yielding over 100 Early Cretaceous bird specimens. Jian changmaensis lived approximately 124 to 120 million years ago and belonged to the Microraptorinae subfamily, a group of small, feathered dromaeosaurids known for their gliding capabilities, similar to its famous relative, Microraptor.

The unearthed fossil provides crucial information about the ancient ecosystem of the Changma Basin. "Jian changmaensis is one of the biggest microraptor specimens that has ever been found," stated Dr. Jingmai O’Connor, a paleontologist affiliated with the Field Museum of Natural History and the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences. She estimates the dinosaur's total wingspan to be around four feet, comparable to a barn owl, based on a 10 cm (4-inch) upper arm bone fragment.

Researchers believe Jian changmaensis, like other microraptors, possessed long feathers on its arms and legs, giving it the appearance of having four wings. While not capable of powered flight, these adaptations likely enabled it to glide effectively, much like modern flying squirrels. The skeletal remains were recovered from the Xiagou Formation, an area near the village of Changma in Gansu province, which has yielded numerous Early Cretaceous bird fossils, many with preserved soft tissues and feathers.

Expanding the Geographic Range of Microraptorinae

Until this discovery, all confirmed members of the Microraptorinae subfamily were found in the Jehol Group, located approximately 2,000 km away in northeastern China. The presence of Jian changmaensis in northwestern China significantly extends the known geographic distribution of this dinosaur lineage. "This new microraptor dinosaur, Jian changmaensis, is our best guess" for the source of peculiar bird bone clusters found at the site, Dr. O’Connor noted. It represents the only non-bird carnivore discovered there, and it was considerably larger than the avian fossils found.

The finding is particularly significant because it provides a missing piece to the paleontological puzzle of the Changma Basin. For years, scientists had collected a wealth of bird fossils but no non-avian dinosaur remains. "Jian changmaensis reveals that non-avian dinosaurs lived in what is now the Changma Basin, an area famous for its fossil birds," explained Dr. Matt Lamanna, a paleontologist at the Carnegie Museum of Natural History. He added, "Our team has recovered more than a hundred bird fossils at Changma, but only this single non-avian dinosaur specimen."

The discovery of Jian changmaensis offers vital new insights into the biological history and ecological context of the Changma region during the Early Cretaceous period. Understanding these ancient ecosystems and the evolutionary relationships between early birds and their non-avian dinosaur relatives is crucial for comprehending the success of modern birds. "Birds are arguably the most successful group of land-dwelling vertebrate animals on Earth today," Dr. O’Connor emphasized. "Learning about early birds and their close non-bird dinosaur relatives gives us a better understanding of what made the group of birds that survived so special." The research detailing this significant paleontological find was published in the latest issue of the Annals of Carnegie Museum.