This is a bdelloid rotifer, a common microscopic animal that lives in freshwater all over the world. But the one seen here is unique in that it was frozen in Arctic permafrost for 24,000 years and just revived by scientists. Once thawed, the rotifer was able to feed and reproduce. The Russian researchers had collected the sleeping creature using a drilling rig in Siberia. From CNN:
"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," said Stas Malavin, a researcher at the Soil Cryology Laboratory at the Pushchino Scientific Center for Biological Research in Russia.
Earlier research by other groups had shown that the rotifers could survive up to 10 years when frozen. In a new study, the Russian researchers used radiocarbon dating to determine that the critters they recovered from the permafrost – ground that is frozen year-round, apart from a thin layer near the surface – were about 24,000 years old[…]
Malavin said that it is highly unlikely bigger life forms could survive being frozen in this way.
"The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to life – a dream of many fiction writers," Malavin said in the statement.RELATED ARTICLEPreserved woolly rhino unearthed in Russian Arctic
"Of course, the more complex the organism, the trickier it is to preserve it alive frozen and, for mammals, it's not currently possible. Yet, moving from a single-celled organism to an organism with a gut and brain, though microscopic, is a big step forward."
A living bdelloid rotifer from 24,000-year-old Arctic permafrost (Current Biology)
image: Michael Plewka