Still think cloning extinct animals is impossible? Technically, it's already been done: the Pyrenean ibex recently became the first extinct animal to ever become un-extinct — at least, for seven minutes. The cloned fetus, which contained reanimated DNA from the last known living Pyrenean ibex, was successfully brought to term after being implanted in the womb of a living domestic goat. Although the ibex died of lung difficulty seven minutes after birth, the breakthrough ensures the inevitability of resurrecting extinct species.
The last known Pyrenean ibex was a female named Celia, who was killed by a falling tree in 2000. It was her DNA that was used to create the short-lived clone.