Scientists pulled the corpse of a fully grown, if partially gnawed upon wooly mammoth from the ice in Siberia recently. This is not wholly unusual, happening more often than we might think, but this one actually possessed some liquid blood. The blood was found in cavities beneath her "belly", enough to allow diggers to put the blood in a vial.
That's the rub of it. We can genetically recreate these creatures, bringing them back to the world they abandoned just a few thousand years ago.
Of course there is a huge moral/ethical debate as to weather we should bring extinct creatures back; whether this would be an unnatural act or even cruel.
The answer is of course, yes we should. How else can we do this . . . .