Fossil Archaeopterix with traces of feathers. [Getty Images]

A fossil Archaeopterix from Germany. On this fossil, traces of the feathers can be seen. (Photo by CM Dixon/Print Collector/Getty Images) — see more

A fossil Archaeopterix from Germany. On this fossil, traces of the feathers can be seen. (Photo by CM Dixon/Print Collector/Getty Images)

Hulton Archive Print Collector