‘Dinosaurs Among Us’ at American Museum of Natural History, Selected by Mark Dion

X-ray studies, including those done by Museum researchers, reveal that baby birds flap their tiny wings to help them climb steep slopes. The force generated by flapping pushes them forward as well as upward, improving traction as they climb. Non-bird dinosaurs might have done the same thing with their mini-wings before flight evolved.

ASHLEY HEERS/BROWN UNIVERSITY XROMM FACILITY