Since manatees swim up creeks to stay warm in the winter in the springs, and flintknappers seek stone in creeks to knap, and Indians used shark teeth as tools and ornaments and also ate manatee meat... it would be expected to find these things in FL creek beds whether or not the area was ever under water.
Sorry, the shark teeth range from about an eighth of an inch up to six or seven inches in length. No indian could use the small ones for anything. Ray plates and turtle shells are also found in the creeks. I once found a skull bone from a spadefish, which was sent to Harvard museum.
At the same time you can find cypress stumps out in the gulf of Mexico, far from land.