Bdelloid rotifer, a microscopic multi-celled super-resilient organism, was thought to survive being frozen for as long as 10 years. Turns out that was a slight understatement. Such female-only organisms are alive and well after being frozen in Siberia for 24,000 years, according to new research. The study published Monday in Current Biology notes they might even survive indefinitely, per the BBC. Researchers dug up dozens of bdelloid rotifers from ancient permafrost, then thawed them in a lab. The animals, which radiocarbon dating showed to be about 24,000 years old, were then able to feed and reproduce asexually, per USA Today. More research is needed to understand how these organisms survive as long as they do, but the idea isn't so strange. Other multi-celled organisms and some plants have been shown to come back to life after thousands of years.
Multi-celled nematode worms were revived from sediments in Siberian permafrost found to be more than 30,000 years old in 2018, while a campion flower was grown from seed tissue thought to have been preserved in permafrost for 32,000 years, reports CNN. But "our report is the hardest proof as of today that multicellular animals could withstand tens of thousands of years in cryptobiosis, the state of almost completely arrested metabolism," says study co-author Stas Malavin of the Pushchino Scientific Center for Biological Research. This doesn't mean a woolly mammoth exposed by thawing permafrost will suddenly resume foraging. "The more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it's not currently possible," Malavin notes. Still, "we revived animals that saw woolly mammoths, which is quite impressive," he tells the New York Times. (Read more discoveries stories.)