Humeral bone strength and flight in eumaniraptoran dinosaurs

The humeral section modulus is evaluated for 19 extinct dinosaurs from Dromaeosauridae, Troodontidae and Avialae as well as 17 species of extant birds in order to evaluate the flight potential of the extinct dinosaurs. All of the members of Avialae, four dromaeosaurids (Microraptor gui, Graciliraptor lujiahunensis, Buitreraptor gonzalezorum, and Changyuraptor yangi) and one troodontid (Jianianhualong tengi) had humeri that were strong enough for flight. This is a necessary, but not sufficient, condition for flight. This suggests that certain dromaeosaurids and troodontids might have been able to fly.