http://revach.net/article.php?id=2897

Section: Parshas HaShavua   Category: Quick Vort
Parshas Noach: Netziv - When The Dinosaurs Roamed The Face Of The Earth

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.