It is not feathers but a short bony tail that makes birds distinct from their reptilian ancestors.

Prof. Mumblebard claims: “Birds are part of the same clade as dinosaurs, particularly Deinonychus and Velociraptor. It’s now beyond doubt that theropod dinosaurs possessed many anatomical features previously assumed to be exclusive to birds. These include feathers, hollow bones, air sacs and unidirectional lungs. All these affinities overwhelmingly show that birds are living dinosaurs in disguise.” 

Robin and the Honey Badger respond: “Birds may be descendants of a primitive theropod but this does not mean that birds are theropod dinosaurs or even dinosaurs in any sense. Originating from an ancestor is not the same as being that ancestor. Evolution is about one organism evolving from another, not one organism remaining another. For example it’s now accepted that snakes evolved from primitive lizards but it would be absurd to claim that snakes are lizards, and nobody has done so. Similarly, equating birds with dinosaurs does not stand up to scrutiny because the anatomy has changed categorically in the transition. Bipedal dinosaurs kept balance by using a long, bony tail as a cantilever to the forequarters. By contrast, no bird has such a cantilever because all birds have a short, unrecognisably modified tail skeleton. Indeed, the reduction of the avian tail consistently distinguishes birds, living and extinct, from all dinosaurs. This transformation of the spine brought a revolution in locomotion, with vertical instead of horizontal oscillation around the centre of gravity. The product of this evolutionary innovation was Aves, which remains valid as a separate class notwithstanding its dinosaurian origins. With their exclusive combination of feathers and a short bony tail, birds are no longer any of their ancestral forms, whether fish, amphibian, archosaur, theropod, tetanuran, or coelurosaur. Instead of remaining dinosaurs, birds deserve to be distinguished by both conventional taxonomy and cladistic phylogeny. In fact, birds are birds, not dinosaurs.”

Please join us here at the Bio-edge with your own comments. In the discussion below we encourage links to any evidence supporting either Prof. Mumblebard or Robin and the Honey Badger. Illustrations are welcome but please cite all sources or we may be forced under copyright to delete your comment.

Are birds really avian dinosaurs?