Archaeopteryx, ancient wing, was the dinosaur-bird that lived in the Late Jurassic of Europe and is one of the most important fossils ever found. The first Archaeopteryx skeleton with feathers was found in 1861, and since then 6 – 7 skeletons have been recovered. The similarity to Compsognathus and other small theropods led to early specimens being classed as theropods until the feather impressions were recognized. The significant similarities between it and birds have heavily weighted current opinion in favor of Archaeopteryx being a bird rather than a non-avian theropod. As well as the features of the pelvis and limbs, the seventh skeleton contained a well-preserved skull which showed a unique combination of features supporting both the theropod origin of birds, and that Archaeopteryx is the most primitive bird yet found.