Netziv Dinosaurs DID exist

There is interest theory’s when discussing the age of the universe and earth. Scientists say that they have proved that the earth is 15 billion years old whereas we Jews believe the world is only 5769 years old. To that the scientists ask how we can explain the fossilized bones of huge creatures such as dinosaurs, and other such so called anomalies! i have always had a theory on this. We all know that the mabul was a phenomenon unlike any other and that the sheer weight of the water (remember that the waters reached as high as 15 amos taller than the tallest mountain on earth) could have easily caused fossilization at a much faster rate then we think possible! To back up my theory there is an interesting Nitziv in Parshas Noach who says that gigantic creatures (dinosaurs?) did actually exist before the Mabul. Hashem left their bones around to be discovered at a later time, in order to show the world the size and strength of these creatures that existed before the great flood.