New Dinosaur Shows Flight Evolved More Than Once

Scientists in China have identified a new species of feathered, four-winged dinosaur that appears to have assembled the machinery of flight on its own—independently of the evolutionary lineage that produced birds. The discovery, published in the journal Nature Communications, challenges a leading hypothesis that birds and their closest dinosaur relatives shared a common developmental blueprint for taking to the air.

The new species, Norellraptor barsboldi, lived roughly 120 million years ago in what is now Liaoning Province in northeastern China. Its nearly complete 57-centimeter (22-inch) skeleton preserves imprints of feathers and, according to the researchers, records a sequence of anatomical changes that ran in the opposite order to the one seen in early birds.

A New Member of the Microraptorines

According to The Paper, the fossil was recovered from the Lower Cretaceous Jiufotang Formation near Lamadong Town in Jianchang County. The team named the genus in honor of the American paleontologist Mark Allen Norell (1957–2025) and the species after the Mongolian paleontologist Rinchen Barsbold (1935–2025), both pioneers in the study of bird-like dinosaurs.

The authors—led by Xuri Wang of Hebei GEO University, alongside Yannan Ji, Andrea Cau of Italy’s OPHIS Paleontological Museum, Martin Kundrát, Yichuan Liu, Yang Wang, and Qiang Ji—assign the animal to the Microraptorinae, a subgroup of small, predatory theropods best known from the Jehol Biota. As members of Paraves, the broader group containing birds and their nearest relatives, microraptorines have long served as model organisms for studying how avian flight began.

According to the study’s abstract, the specimen died as a post-juvenile individual, based on bone histology, fully fused lower leg bones, and smooth bone texture. Its plumage was preserved near the right humerus, the hip, the tail, and the right foot. The tail feathers display a rachis-dominated morphology—a central shaft with barbs—while the forelimb likely bore asymmetrical pennaceous feathers.

Two Lineages, Opposite Sequences

The heart of the study lies in a comparison of evolutionary sequences. The researchers counted 194 anatomical changes along the microraptorine branch of the dinosaur family tree. Of these, 57 features—roughly 30%—were also acquired convergently by the bird lineage, Avialae.

But the order in which those flight-related features appeared differs consistently between the two groups. As Rapid Press reported, microraptorines shortened their hand and finger bones early, only later fusing the wrist and hand bones needed to reinforce powered flight. Early birds did the reverse: they fused the sternum and wrist bones first and shortened their fingers much later.

The paper’s subtitle—“Independent assembly of the flight apparatus in a non-avian dinosaur clade”—states the conclusion directly. “The sequences of flight-related novelties reconstructed along the two lineages differ consistently,” the authors write in the abstract, adding that the evidence “dismisses a shared developmental pattern driving the evolution of the flying dinosaurs and support[s] multiple and independent selective regimes at the origin of the winged taxa in Paraves.”

Overturning a Leading Hypothesis

Three competing explanations have framed the debate over how microraptorines became airborne. One holds that a rudimentary flight ability arose in the shared ancestor of birds and near-birds and was inherited and refined, then lost by non-flying relatives. A second holds that flight evolved separately in different dinosaur branches, with superficial similarity reflecting convergence driven by the same aerodynamic demands. A third—the deep homology or developmental-constraint hypothesis—proposes that even if flight evolved more than once, near-birds shared a conserved embryonic regulatory program that pushed both lineages along the same evolutionary path.

The new analysis directly tests that third idea, and finds it wanting. “The findings challenge the idea that microraptorines and birds inherited either a common flight apparatus or a shared developmental process that drove its evolution,” the researchers said, according to Rapid Press. “Different selective pressures probably shaped the flight-related features of each lineage.”

Histological analysis of the left radius added a further clue. According to the study, the bone shows a peculiar limb-growth model and extensive pneumatization—air-filled cavities—suggesting microraptorines may have followed their own developmental route rather than retracing an avian program.

A Peculiar Anatomy

The skeleton itself combines features that hint at both gliding and agile running. Among its diagnostic traits, per the Wikipedia entry on the genus, is a large promaxillary fenestra—an opening in the skull occupying the entire front third of the antorbital fossa—together with a gently curved pubis bearing a small foot and an arctometatarsalian tarsometatarsus, in which the third metatarsal is strongly constricted near its top. The animal nests among late-diverging microraptorines and is the sister taxon to Zhongjianosaurus.

Norellraptor lived in a temperate, forested environment. Its contemporaries in the Jiufotang ecosystem included the tyrannosauroid Sinotyrannus, the early mammal Liaoconodon, the ceratopsian Psittacosaurus, and a wide array of early birds and pterosaurs.

Why It Matters

Flight is one of evolution’s most demanding innovations, requiring the coordinated refinement of feathers, limbs, muscles, and skeleton. If that apparatus can be assembled along more than one developmental path yet still arrive at a working wing, it suggests natural selection can reach similar aerodynamic solutions from very different starting points.

The finding also has implications beyond dinosaurs. Recurring similarity between close relatives is often read as a sign of shared ancestry—or, subtler still, of a conserved developmental program that channels evolution in a preferred direction. Norellraptor suggests that even when the same features reappear, the road taken to reach them may be entirely different.

What to Watch

The authors caution that key questions remain open. The precise function of Norellraptor’s wing feathers—whether they enabled gliding, powered flight, or something in between—is still uncertain, and only a single specimen is known, so it is unknown whether elongated feathers formed a distinct second pair of wings on the hindlimbs. The team says further fossil and bone-growth evidence is needed to test how widespread the inverted assembly pattern is among bird-like dinosaurs.

For now, Norellraptor barsboldi stands as a reminder that the story of how animals first took to the skies was written more than once—and not always in the same order.