Two of the prehistoric worms defrosted by Russian scientists woke up.

While many experts said that the researchers’ claims are feasible, further testing should be conducted to definitively assess the worms’ age.

While many experts said that the researchers’ claims are feasible, further testing should be conducted to definitively assess the worms’ age.In July 2018, The Siberian Times reported that two nematodes, or roundworms, preserved in the Arctic permafrost for around 40,000 years, allegedly came back to life after being “defrosted” by researchers.

New Atlas’ Michael Irving told SmithsonianMag, "A team of Russian scientists working in collaboration with Princeton University found the viable specimens while analyzing more than 300 soil samples taken from the Arctic permafrost. One of the samples was retrieved from a squirrel burrow located in the Duvanny Yar outcrop and dates to about 32,000 years ago. The older sample, which dates to about 41,700 years ago, was found in a glacial deposit near the Alazeya River. Both nematodes are believed to be female."

The findings, which appeared in the Doklady Biological Sciences journal in July 2018, was the first supposed evidence on the capability of multicellular organisms for longterm cryobiosis in permafrost deposits of the Arctic.

According to the research, that ability suggested that the Pleistocene nematodes had some adaptive mechanisms that might have been of scientific and practical importance for the related fields of science, such as cryo-medicine, cryobiology, and astrobiology. The scientists reported they could not rule out the possibility that the samples were contaminated at a relatively recent point and kept the experiment as sterile as possible.

However, there are no further credible reports to support the result. The universities which were involved in the research have not published an update or reported any data on the discovery. The published data by Doklady Biological Sciences has not been peer-reviewed. There have been no updates since 2018, and as of now, the claim on frozen nematodes is unverifiable.