If it's a modified bird, then I think the rules of taxonomy would count it as a bird no matter how much it looks and acts like a non avian dinosaur. (Not that we could totally tell, since we don't have one to compare it too)

(And no, it can't just be a bird.)

By what definition of bird? Neornithes (the most recent common ancestor of all currently living birds and all its descendants)? Avialae (all dinosaurs with feathered wings capable of powered flight and descendants thereof)? Something in between?

Baby steps

https://en.wikipedia.org/wiki/Romulus,_Remus,_and_Khaleesi

You might want to add "prehistoric" to the title as well, just to make it extra clear that birds don't count

Would something engineered to have be very similar to a dinosaur count, or do we actually need to get a dinosaur's mostly intact DNA?

The DNA needs to be similar enough that biologists would classify it genetically as a dinosaur. It doesn't need to be an exact clone of an original dinosaur's DNA; it could also be some sort of reconstruction that gets close. But it can't be, say, a silicon-based life form that looks and behaves exactly like a T-rex.

@IsaacKing I am more thinking what if we take existing avian genomes, make edits to it until we get a Tyrannosaur phenotype, but there's no ground truth available for whether this is close to an actual Tyrannosaur genome. Or, more generally: is there any way for this to resolve YES without us recovering a mostly-intact dinosaur genome?

@vluzko Sorry, I never responded to this. That would count.

This is so disappointing.