You would think that something as significant as the birth of all human culture taking place after the dispersal from Noah's ark would be noticed. Sure enough, that's what the record of history tells us happened.
Scattered Abroad
Dinosaurs in Idumea
Depending on which English Bible translation you read, you may or may not see the word dragon occur. Several Hebrew words are translated dragon in the KJV, but are rendered as various other creatures in newer translations.
Extinction of Giant Land Reptiles
Behold Behemoth, a Sauropod dinosaur which lived in the Jordan valley during the time of Job and Abraham. Clearly not all of the giant land reptiles were made extinct by Noah's flood.