Norellraptor fossil reshapes the sequence of wing evolution
A newly described feathered Norellraptor from China adds a comparison point for wing-related traits in microraptorines and the bird lineage. Bone tissue and evolutionary-tree analyses favor different sequences of change. An independent paleontologist cautions that separate origins are not settled. Fossil anatomy does not directly show how the living animal moved through the air.
Science··Morning
A new fossil enters the winged family tree
Norellraptor barsboldi is a small predatory dinosaur with unusually well preserved feathers and bones, recovered from northeastern China’s Jiufotang Formation. The specimen is about 57 centimeters long and belongs among microraptorines, rather than being identified as a direct ancestor of birds. Long feathers on the forelimbs and hindlimbs give researchers structures relevant to possible aerial movement. Its position on the family tree adds a comparison point for asking when similar wing features arose in each branch.[1], [2]
Bone tissue points to different sequences
Researchers examined Norellraptor forelimb bone tissue and anatomical traits. They estimate that roughly 30 percent of traits defining microraptorines may also have arisen independently in the bird lineage. The order in which anatomical novelties appeared differs between the branches. Similar outlines therefore need not be an unchanged wing package inherited from one ancestor. Internal bone structure adds a clue about growth, but feathers and bones cannot record the motion of a living animal.[1], [2]
Flight mechanics and origins remain open
Independent paleontologist Jesús Marugán values the detailed anatomical work but cautions that proving wholly separate origins of the wing arrangements remains difficult. Other specialists discuss possible combinations of gliding and flapping. The study thus supports an evolutionary interpretation in which flight-related structures followed different routes in two lineages. It does not experimentally establish sustained powered flight by Norellraptor. Reconstructing that behavior would require further evidence within the limits of what fossils can preserve.[1], [2]
