Ice Age cave lion cubs Sparta (foreground) and Boris, which were found by people hunting for mammoth tusks in the Yakutia region of north-eastern Russia. Sparta lived about 28,000 years ago and Boris 43,000 years ago. Photograph: Daniel McLaughlin

Blasted from their permafrost graves by men hunting mammoth tusks, Sparta and Boris, two cave lion cubs who lived tens of thousands of years ago, are (...)