Archaeopteryx
Thomas Henry Huxley ("Darwin's bulldog"), who was a comparative anatomist, made a study of this nearly 150 years ago. He compared Archaeopteryx with a small theropod dinosaur, Compsognathus. Both of the fossils came from the same place: Solnhofen in Bavaria, Germany. The strata come from the end of the Jurassic period, about 144 million years ago. He showed that both were very similar except for the front limbs and feathers of Archaeopteryx. E.D. Cope also came to the same conclusion.