"Dinosaurs became extinct long before Noah's Ark"
But am I correct that you're also saying "dinosaurs and mammals lived together in harmony in the Garden of Eden until..."?
Yes, I do believe that dinosaurs and mammals did live together in harmony while living in the Garden of Eden.
Dinosaurs were probably vegetarians and not carnivorous.
It was after Adam and Eve sinned that everything began to change for the worse.
Again, that is my humble opinion, I could be wrong. The Garden of Eden was described as “paradise” so I do not believe that there was any blood shed between animals.