Einstein presented his theory of relativity in 1916, but for an entire century nobody could find physical proof of black holes. In 2016, scientists finally detected gravitational waves that emitted from 2 black holes colliding, proving that such things not only exist, but that Einstein was right all along. Source

99-million-year-old bird wings were discovered perfectly preserved in amber. It’s the first time feathers this old have been found in such condition, making them primary examples of hair follicles and feather arrangements from the Cretaceous period. Most fossil wings are preserved in only two dimensions, and soft tissues like feathers rarely survive falling into amber. Source