Theropod Origin of Birds

The discovery of archaeopteryx 2 years after Darwin published his theory of evolution initiated the argument that birds were of theropod descent. This creature, while reptilian in nature, had wings with asymmetrical pattern (flight) as well as a larger skull which presumably housed a larger brain.  The prevailing alternative hypothesis states that thecodonts are potential ancestors  due to their large, wing-like scales found on their dorsal aspects. Following this discovery, multiple fossils of feathered dinosaurs were uncovered including sinosauropteryx,  protarchaeopteryx, caudipteryx as well as several microraptor skeletons that all contributed their own unique clues which supported the theropod descent theory.