Genetics: Ancient squirrel droppings reveal rich prehistoric ecosystem (Nature Communications)
10 June 2026
Squirrel droppings preserved in Canadian permafrost containing 700,000-year-old ancient DNA are reported in Nature Communications. The findings, which include DNA from woolly mammoths, horses, American cheetahs, and steppe bison, enable the reconstruction of vibrant and diverse ancient ecosystems and shed new light on the evolutionary history of certain species.
Coprolites, or fossilised faeces, can preserve a variety of biomolecules from ancient animals, including ancient DNA from both the defecator and the surrounding environment. However, coprolites are less commonly used for ancient DNA analysis than bones or sediments because they degrade more easily. In Arctic regions, ground squirrel burrows can remain frozen and sealed for thousands of years, allowing genetic material in coprolites to be preserved.
Tyler Murchie and colleagues analysed 13 Arctic ground squirrel (Urocitellus parryii) coprolite samples from central Yukon in Canada. This research was conducted with permission from the Tr’ondëk Hwëch’in First Nation, within whose traditional territory the study occurred. They identified DNA from a wide range of plants, microbes, insects, and animals, including megafauna such as woolly mammoths, horses, American cheetahs, and steppe bison, as well as more than 200 different plant groups. The authors were able to reconstruct 18 mitochondrial genomes from the coprolite samples, including twelve ground squirrel (Urocitellus), one hare (Lepus), two bison (Bison), and three horses (Equus). The genomes recovered from Urocitellus point to a rich diversity in Arctic ground squirrels, including a potentially new lineage dating to approximately 700,000 years ago.
The authors note that some of the DNA may have been picked up from the surface of the coprolite at a later time, and that incomplete reference databases may affect species identification. They acknowledge that further work is needed to refine and expand these techniques. However, these results suggest that permafrost coprolites can be effectively used to create high-resolution snapshots of prehistoric environments and complement insights from sedimentary and skeletal ancient DNA.
- Article
- Open access
- Published: 09 June 2026
Murchie, T.J., Cocker, S.L., Baleka, S. et al. Ground squirrel coprolites preserve complex archives of ancient environmental DNA over 700,000 years. Nat Commun 17, 4868 (2026). https://doi.org/10.1038/s41467-026-72977-6
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