One of the clearest transitional forms between dinosaurs and birds that has been discovered so far. Fossils have been found with beautifully preserved feathers, and it is essentially these alone that prevent it from being classified as a dinosaur.

It’s not only the solely presence of feathers though (as there were other contemporary or even earlier dinosaurs with feathers); it’s the fact that they start being specialized for flight.

Other than that, Archeopteryx is as non-avian dinosaur as possible since it has a toothed beak and the dino-type long tail, without a pygostyle.

oh, yes! that’s exactly what i meant haha i should have specified, thankyou :>