Some species are too tasty for their own good. Scientists think they've finally discovered the fate of the giant prehistoric kangaroo. The Times of London reports that these huge marsupials stood 6'5", weighed in at over 500lbs, and practically marinated themselves by consuming saltbush grass. An international team of scientists who published this week in Proceedings of the National Academy of Sciences, believe they've finally hit on the reason the species went extinct 45,000 years ago. The marsupials' eating habits suggest that the giant kangaroo drank more water and therefore spent more time at waterholes, making them vulnerable to hunters. The scientific team concluded that "human hunting was a much more likely extinction cause" than changing environmental conditions.