Finding well-preserved ancient animals in thawing permafrost isn't all that uncommon in Siberia. For instance, woolly mammoths, woolly rhinos, and cave lions have been found remarkably intact, as if frozen in time. But when those woolly mammoths thaw, they don't start walking around.

So you might imagine the surprise of scientists when a pair of ancient nematode worms suddenly started wiggling around shortly after being thawed from Siberian permafrost that had been frozen for tens of thousands of years.

"After being defrosted, the nematodes showed signs of life," said a report that was later detailed in the Siberian Times. "They started moving and eating."

One would imagine that they'd be hungry after not having eaten since the Pleistocene Age.

Scientists at a laboratory at the Institute of Physico-Chemical and Biological Problems of Soil Science in Moscow were examining samples of permafrost containing prehistoric worms when the resurrections occurred. Of the 300 or so worms examined in the study, only two were revived. Still, it's an extraordinary event. One of the worms was found in permafrost dated at around 32,000 years, while the other was thawed from 42,000-year-old frozen soil.

Needless to say, the moment these worms started wiggling, they became the oldest known live animals on Earth. The last time they squirmed through the soil, it could have been beneath the footsteps of a woolly mammoth.

"It is obvious that this ability suggests that the Pleistocene nematodes have some adaptive mechanisms that may be of scientific and practical importance for the related fields of science, such as cryomedicine, cryobiology, and astrobiology,” the report speculated.

It's the first time multicellular creatures of any kind have been shown capable of surviving such long periods of time frozen in suspended animation. Studying the mechanisms that allowed these worms to survive could alter many of our theories about the kinds of worlds where extraterrestrial life might exist. We might even make breakthroughs in cryogenics.

At the very least, the finding is a chilling reminder that as global warming sets in and permafrost melts, these worms may not come alone. Who knows what other strange critters might come crawling out of the thaw.

Worms frozen in permafrost for 42,000 years brought back to life
The last time they squirmed was in the Pleistocene Age.