We often hear people say that modern birds evolved from some dinosaurs. Apart from both being reptiles, what evidence have paleontologist discovered that validates this claim?

A small bird-like dinosaur, called the archaeopteryx (left), lived in what is now southern Germany about 150 million years ago. About the size of a crow, it had a shortened tail, long hands, a perching toe slightly turned backward, and wing feathers that were adapted for flight. This creature has long been considered the most ancient bird known. However, despite its birdlike characteristics, its body more closely resembled those of small meat-eating dinosaurs than those of more birdlike dinosaurs. Many paleontologists identify the archaeopteryx as the so-called missing ...