Many times I find myself with a large number of opened tabs in Firefox browsers and thankfully you don't need to close the program in order to close all the tabs except the one I want to keep.
The newest findings suggest that a cosmic impact of an asteroid or comet, indeed was the reason why the once mighty dinosaurs don't roam the planet Earth anymore.
Speculating about future is is most of the time futile, let alone about the distant 100,000 years kind of future. But we can always guess and if there is science involved we even might be onto something.
You deleted everything from your USB key or a drive, so there should be enough free space to copy the new files, but you still get the not enough free space message in Mac OS X? This is what you need to do.