Nomingia gobiensis

Nomingia is an oviraptorosaur from the Late Cretaceous of Mongolia. While today we know that all oviraptorosaurs had feathers, likely including vaned wing and tail-fan feathers, Nomingia was among the first non-avian dinosaurs found to possess a pygostyle — a fused tail-tip that anchors tail feathers in birds. Given that Nomingia was clearly not a flying animal, it also should break any proposed link between having a pygostyle and flight, unless the rest of the animal’s anatomy supports it.