I have my own theory on that one. I am going to render a guess as to what happened.
Antarctic Ice Cap Melting From Within, History A Vast Early Warning System, Ever Heard Of A Guy Named Noah?
Of course there are many giant stories
De Vaca tells of astounding raids on giant native Americans in Florida. He was attempting to cross a very large lake (could be Lake Okeechobee) when attacked by giant indians. De Soto thought Tuscaloosa’s son was a giant until he saw Tuscaloosa himself!