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

This extraordinary fossil of a Byronosaurus nest, discovered in Mongolia, preserves a recently hatched animal atop the eggs of what would have been its nest mates. The eggs are not paired, suggesting the egg-layer had only one egg tube—the modern bird condition. The tiny animal is a troodontid, which is a group of small, feathered, non-bird dinosaurs with large brains.