>>110673326Triceratops has a beak, velociraptor, anchiornis, hesperornis, and yutyrannus had feathers.
Any rule with exceptions can't be used.
Dinosaur definitively includes every animal descended from the common ancestor of saurischia and ornithischia. It's so fucking vague that physical descriptors stopped working
You need diagnostic or universal traits. Your proposal sounds solid to me personally, but there's frankly too many loose descriptors.
There were birds with solid tails and clawed wings up until the middle of the cenozoic. There are birds with clawed wings today, are they not birds anymore?
How about other mutations? Ostriches have clawed hands concealed under the wing, are they dinosaurs now?
It's impossible to determine if dinosaurs were flightless, literally impossible. Yi qi has gone back and forth since its discovery.
All dinosaurs under the class maniraptora had true wings no different from an ostrich, are they birds now? Is Velociraptor a bird?
Does an animal need a combination of all of these traits? Doesn't that move the first bird from the mid jurassic to the late cenozoic?
