i have heard many times that dinosaurs existed and were destroyed in the Mabul because they were the result of immorality at the time which occurred even between the animals ( animals mating with other animals not their own )
Do you know of a makor for that?
1 - ה' told Noach to take "
מכל החי" which would seem to refute that pshat.
2 - from a scientific perspective, dating of the fossils would seem to indicate that they are older than that, although that might be explained by the changing circumstances (including the mabul itself) which might make them seem older, and the difficulty in extrapolating from a limited perspective.