I've annotated with a yellow star in the images above a rodent's nest, found underground in the permafrost of Siberia. From that nest scientists isolated a roundworm (a nematode), which wiggled to life after being warmed.
Organisms from diverse taxonomic groups can survive extreme environmental conditions, such as the complete absence of water or oxygen, high temperature, freezing, or extreme salinity. The survival strategies of such organisms include a state known as suspended animation or cryptobiosis, in which they reduce metabolism to an undetectable level. Spectacular examples of long-term cryptobiosis include a Bacillus spore that was preserved in the abdomen of bees buried in amber for 25 to 40 million years, and a 1000 to 1500 years-old Lotus seed, found in an ancient lake, that was subsequently able to germinate. Metazoans such as tardigrades, rotifers, and nematodes are also known for remaining in cryptobiosis for prolonged periods. The longest records of cryptobiosis in nematodes are reported for the Antarctic species Plectus murrayi (25.5 years in moss frozen at -20°C), and Tylenchus polyhypnus (39 years desiccated in an herbarium specimen).
And the fact that the creature is parthenogenic raises other interesting aspects:
In summary, our findings indicate that by adapting to survive cryptobiotic state for short time frames in environments like permafrost, some nematode species gained the potential for individual worms to remain in the state for geological timeframes. This raises the question of whether there is an upper limit to the length of time an individual can remain in the cryptobiotic state. Long timespans may be limited only by drastic changes to the environment such as strong fluctuations in ambient temperature, natural radioactivity, or other abiotic factors. These findings have implications for our understanding of evolutionary processes, as generation times may be stretched from days to millennia, and long-term survival of individuals of species can lead to the refoundation of otherwise extinct lineages. This is particularly interesting in the case of parthenogenetic species, as each individual can find a new population without the need for mate finding, i.e. evading the cost of sex. Finally, understanding the precise mechanisms of long-term cryptobiosis and cues that lead to successful revivals can inform new methods for long term storage of cells and tissues.
Detailed information and discussion in the PLOS Genetics article (not behind a paywall).
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