Imagine a world overrun by 9-foot flightless birds, 17-foot giant beavers and predatory marsupial lions as tall as elephants! Two million years ago, these enormous creatures - Mega Beasts - roamed the continents in bursting populations. Despite the fact that each gargantuan species is now extinct, the mystery of their demise lives on. Watch the most rivetingly realistic computer animation available as What Killed the Mega Beasts? takes you on a fascinating journey through time. Now you too can attempt to solve one of the greatest riddles ever, one that to this day keeps scientist from Patagonia to Colorado to New Zealand debating and searching for answers. Join us as we explore these questions: Is it the "Chill Theory," which argues that profound climactic change accounts for the death of the Mega Beasts? Is it the fact that big animals adapt to environmental changes less easily than do smaller ones? What if a "killer virus" swept away these extraordinary, fearsome beings? Or, finally, as those who ascribe to the "Kill Theory" assert, is it possible that the Mega Beasts were slaughtered by a creature more terrifying than any other - man?