Remarkable Fossil of a Feathered, Winged Dinosaur Further Hints That Flight Evolved Multiple Times Among the 'Terrible Lizards'

An extremely well-preserved dinosaur fossil is further fueling the debate about the evolution of flight among the “terrible lizards.” The new species of feathered, bird-like predator—dubbed Norellraptor barsboldi—adds to mounting evidence that dinosaurs independently evolved their aerodynamic capabilities multiple times. Researchers describe the findings in a study published September 29 in the journal Nature Communications. Scientists have long wondered how many times birds and their relatives developed the ability to take to the skies, which is relatively rare among animals.

Dinosaurs called microraptors can help answer that question because they were close cousins of birds but not their ancestors. (Birds and their direct dinosaur ancestors are called avialans.) The ancient beasts had adaptations associated with flight, like certain limb features and plumage. But scientists have argued over the evolutionary relationships between shared traits in these dinosaurs and birds, which are our best model of how the extinct animals may have flown. The genus name Norellraptor honors the late American paleontologist Mark Allen Norell, and the species name barsboldi refers to the late Mongolian paleontologist Rinchen Barsbold.

Both made major contributions to the study of bird-like dinosaurs. A paper published in 2021 created an evolutionary tree of dinosaurs related to birds and found that the “terrible lizards” may have evolved flight at least three separate times. Researchers found the microraptor N. barsboldi in northeastern China in rock dated to around 100 million to 145 million years ago.

It was at least 3 years old when it died and quite small, with a roughly 22-inch-long skeleton. The creature had four wings, a long tail, and sharp teeth and claws. It probably ate tiny creatures, such as early mammals, lizards, amphibians and young dinosaurs, Scott Hartman, a vertebrate paleontologist at the University of Wisconsin-Madison who wasn’t involved in the new research, tells Live Science’s Chris Simms.

Thanks to the well-preserved fossil, researchers created an updated evolutionary tree of microraptors. Analyses revealed 194 anatomical adaptations that arose in the group—about 30 percent of which also popped up in bird evolution. They include things like a certain forearm bone being longer than an upper arm bone and the fusion of specific wrist and hand bones.

However, the researchers found that the overlapping features evolved in different orders in the two groups, hinting that they did not come from a cp,,pm ancestor. Rather, they may have both developed flight independently because of similar environmental pressures, a phenomenon called convergent evolution. The study “demonstrates that microraptors acquired traits convergent with the early evolutionary stages of true birds, albeit through a distinct evolutionary pathway, supporting the hypothesis that flapping flight evolved independently in non-avialan dinosaurs and birds,” Rui Pei, a paleontologist at the Chinese Academy of Sciences who didn’t participate in the study, tells Live Science.