Scientists have uncovered a remarkably well-preserved fossil of a small, feathered dinosaur in northeastern China that could alter prevailing theories about the evolution of flight in dinosaurs. The newly identified species, named Norellraptor barsboldi, lived approximately 100 million years ago during the Lower Cretaceous period. Measuring about 57 centimeters in length, this four-winged predator belongs to the microraptorines, a group of small, feathered dinosaurs closely related to birds.
The fossil was excavated from the Jiufotang Formation in Liaoning province, a geological site renowned for its exceptional preservation of Early Cretaceous fossils from the Jehol Biota ecosystem. The specimen includes a nearly complete skeleton along with significant portions of its plumage, enabling detailed analysis of its anatomical features linked to flight.
A multinational team of researchers from China, Italy, and Slovakia described their findings in the journal Nature Communications on Tuesday. Their study provides new evidence supporting the idea that flight evolved independently in different paravian lineages rather than from a single common origin. Paraves is the clade that encompasses birds and their closest relatives, including microraptorines.
Previous research has shown that some microraptorines possessed long feathers on both their forelimbs and hindlimbs, adaptations thought to play a role in aerial locomotion. However, scientists had debated whether these traits signified a shared developmental pattern with birds or whether they evolved separately as distinct evolutionary experiments in flight.
The recent analysis revealed notable differences in how flight-related features appeared in birds compared to microraptorines. For example, birds initially developed fused wrist bones and elongated breastbones before shortening their hand digits, whereas microraptorines shortened their manual phalanges, or finger bones, earlier in their evolutionary history—a modification that reduced their grasping ability. This suggests that despite sharing about 30% of anatomical flight-related changes, the two groups achieved these adaptations through different sequences of evolutionary changes.
Researchers interpret these findings as evidence that separate selective pressures influenced the emergence of flight in these lineages, rather than a common developmental program driving the evolution of wings. They emphasize the need to examine additional fossils across birdlike dinosaurs to better understand how widespread this pattern of independent flight evolution may have been.
The species was named Norellraptor barsboldi in honor of American paleontologist Mark Allen Norell and Mongolian paleontologist Rinchen Barsbold, both of whom passed away in 2025 and are recognized for their significant contributions to the study of birdlike dinosaurs. The fossil specimen analyzed was at least three years old at the time of death, offering important insights into the growth and development of flight-related features within this group.