semyon grigoriev dreams of bringing back these woolly giants. up an international center for mammoth studies here in yakutsk. he's stored his most important specimen at minus 86 degrees celsius. it's a fully grown female mammoth, which the scientists have named buttercup. grigoriev says buttercup's trunk is a real treasure trove. semyon grigoriev: when we cut into it, we found a number of areas where the flesh was still red. we found real muscle tissue, that's amazing. this trunk offers our best hope of finding living cells. reporter: it was 2013 when semyon grigoriev made what he says was the most amazing discovery of his life. only buttercup's tusks were protruding out of the ice. the rest of her was buried in the permafrost on an island in northern siberia. when the team of scientists removed the ice underneath the mammoth's stomach, they witnessed something that had never happened before. dark blood came trickling out of the ice. amazingly, it wasn't frozen. ♪ reporter: grigoriev later discovered that the carcass was over 28,000 years old. h