"What Is It???" Wednesday

Roaming the Museum of Florida History last week I saw several artifacts that make for good WIIW fodder.  These two object are not cannon balls, they are stone tools found commonly throughout and world.  These were found in Florida and are currently on display.  They probably measure three to four inches in diameter.

Roll up your sleeves and flex your archaeological muscles to show off if you know what they are, how they were used, and when they were used.

And because I'm obliged to do so, I must shout:

WHAT IS IT????