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AnimalsSurprise 5/5Difficulty 4/5Reviewed on October 17, 2026

In 2021, scientists revived microscopic rotifers that had been frozen for about 24,000 years in Siberian permafrost.

Why it is true

The animals, bdelloid rotifers, were taken from a sample of frozen soil 3.5 metres deep. Once thawed, they started moving again and reproduced by cloning, without any need for males.

Source: Current Biology (Shmakova et al., 2021)

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