A baby woolly mammoth, frozen in soil for 40,000 years in Siberia, was so well preserved that traces of her mother's milk were still in her stomach.
Lyuba, who was thought to be just one month old, was discovered three years ago when nomadic reindeer dug her up. Scientists believe she died after being sucked into a river bed. Mud was found in her trunk and throat, suggesting she had suffocated.
The body is preserved enough to provide DNA samples, but the prospect of cloning the creature is still a long way off. Researchers found the animals' hump acted like a furnace, which helped maintain body temperature during colder weather. This supports the theory that mammoths were born in early spring.
Lyuba is being transported to Chicago to be exhibited in the Field Museum, where she will be the star attraction at a mammoths and mastodons exhibit. Daniel Fisher, the lead curator of the team studying the mammoth, said: "There's a visceral awe that takes hold of you looking at a specimen like Lyuba.
"The exhibition as a whole demonstrates how close we can come to knowing what these animals were like."
As the body was so well preserved, researchers have already learned more about mammoths from it than any previous discoveries.
"We had no idea from preserved skeletons and preserved carcasses that young mammoths had a discrete structure on the back of the head of brown fat cells," Mr Fisher told reporters.
Lyuba is going to be exhibited in 10 cities across the world, with the final stop on the tour being London's Natural History Museum in 2014.
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