A group of Russian scientists have successfully revived two species of tiny worms that they discovered suspended in an icy chunk of Siberian permafrost.
The worms, known as nematodes or more commonly as roundworms, had been frozen for up to 42,000 years, since a time when much of the planet was covered in ice.
But they weren’t dead – just cyrogenically preserved.
The researchers brought the worms back to a lab, where they slowly thawed them over several weeks. The researchers put them in petri dishes with food, stored at 20 degrees Celsius (68 degrees Fahrenheit).
As they warmed, the worms started showing signs of life, moving and eating. That marks the first documented time multi-cellular organisms have returned to functioning after being frozen in permafrost.