First the Bible says that ALL land dwelling animals were on the ark. Dinosaurs were land dwelling animals so they went on the ark. There were only two of each animal or seven of the clean. After the animals came off the ark, the dinosaurs came with them. After that the dinosaurs died. Animals go extinct all the time so that is nothing unusual. Maybe the harsh conditions after the flood made it hard for them to survive and find food. However I do believe that the dinosaur fossils that we find are a result of the global flood.
That logically has to be true. Had they died in anything but a mass catastrophic event, there wouldn't have been any carcass to fossilize.
So, let me get this straight. It was preposterous to conclude that the dinosaurs became extinct because they were denied a ride on the ark, but it is not preposterous to conclude that they therefore must have been on the ark? It is also equally preposterous to conclude that the story was allegorical and that the fossil evidence that demonstrates that a pair of dinosaurs, that represent the size and variety of all dinosaurs that ever lived would have swamped a hundred arks?