Independent assembly of the flight apparatus in a non-avian dinosaur clade.

Independent evolution of flight-related features in microraptorine dinosaurs and birds is supported by osteohistological evidence, with about 30% of traits convergently acquired.

• Why it matters: Understanding whether flight evolved once or multiple times among paravians is crucial for reconstructing avian origins and evolutionary pathways. Clarifying this helps resolve debates about the developmental and adaptive processes behind flight in dinosaurs and birds.
• What they did: The study examined forelimb osteohistology of Norellraptor barsboldi, a late-diverging microraptorine, and compared it with bird lineages, analyzing the sequence and development of flight-related traits across 30% of shared features.
• The result: Findings indicate that flight adaptations evolved independently in microraptorines and birds, dismissing a shared developmental pattern and implying multiple selective regimes drove the emergence of winged dinosaurs.