Scientists in the U.S. have discovered the genetic code of the woolly mammoth, an animal that's been extinct since the Ice Age. It's led to fevered speculation that there might one day be hope of reviving it.

Scientists have pieced together 80 per cent of the mammoth's genome, using DNA samples from hair preserved over ten thousands of years in the Siberian permafrost.

It raises the prospect that it may one day be possible to resurrect these creatures as well as some other species that died out at the end of the last ice age.

The research also revealed that mammoths were more closely related to modern elephants than had been thought.

The million-dollar project is a first draft, detailing more than three billion DNA building blocks of the mammoth, the study published in Thursday's journal Nature says. It's not finished yet, but that's already enough to give scientists new clues on the timing of evolution and the reasons behind ancient creatures’ extinction.