While discussing with Los_cat (my hubby) whether (1) birds came from dinosaurs, (2) shared a common ancestor with dinosaurs, or (3) shared a common ancestor with crocodilians (because of a similar inner ear structure, but this is most likely due to convergence), I decided that The Tick was only partly right when he called science a two headed beast. In fact, science is a many-headed beast which bickers with itself, but stems from a common body of knowledge.
Eventually, there will come a consensus on which of the three hypothesis are correct as the body gets bigger, and more evidence is examined. Personally, I'd go with number one at this point, based on the number of dinosaurs with feathers, wishbones, and front limbs that folded back like birds (Maniraptorans especially). Also, you can't really tell a dinosaur from a early bird without the feathers (archaeopteryx was initially classified as a dino until they found one with feathers). Finally most early birds showed up 45 million years after dinosaurs were established. But if they find older birds, than I may have to revise my position to two.
(Picture: Microraptor, a dromaeosaurid dinosaur fossil, from Liaoning, China on tour in 'Dinosaurs: Ancient Fossils, New Discoveries')
