2001: A SPACE ODYSSEY - Stanley Kubrick and Arthur C. Clark

"The remorseless drought had lasted now for ten million years,
and would not end for another million. The reign of the ter-
rible lizards had long since passed, but here on the continent
which would one day be known as Africa, the battle for survival
had reached a new climax of ferocity, and the victor was not
yet in sight. In this dry and barren land, only the small or
the swift or the fierce could flourish, or even hope to exist."

http://www.scifiscripts.com/scripts/2001.txt