Archaeopteryx is a fossil animal that became famous because it had a combination of reptilian and distinctly bird-like characteristics, which implied support for Darwin's theory of natural selection. Scientists initially hailed it as the first bird. Today, scientists classify all dinosaurs as birds, and some of Archaeopteryx's bird-like traits have been discovered in subsequent fossils of animals once considered entirely reptilian in appearance.
Hermann von Meyer, a German palaeontologist, studied the first Archaeopteryx fossil ever discovered in 1861. The fossil was remarkable because it clearly preserved the impression of delicate feathers within the stone. Darwin's "The Origin of Species" had been published in 1859, generating great debate and controversy. The fossil animal examined by von Meyer, with its mouth full of teeth, long tail and feathery, clawed arms, appeared to be a true missing link between reptiles and birds. Scientists today recognize that there are too many bird-like traits found amongst the clade Dinosauria to classify them as anything other than birds. Many dinosaurs, especially those in the maniraptor group, such as Velociraptor, had feathers and even wings. In fact, maniraptors are actually considered the direct ancestors of birds instead of Archaeopteryx, which is now considered an offshoot. The birds we see today are considered to be avian dinosaurs, whereas animals such as Stegosaurus, which had fewer modern bird traits, are called non-avian dinosaurs.