Dormice may have hibernated as early as 34 million years ago

[Still Waters]

In analyzing rodent fossils, scientists funded by the Swiss National Science Foundation have come up with a novel hypothesis: hibernation was a survival strategy 34 million years ago.

Until very recently, the ability to hibernate was thought to have appeared during the Quaternary ice age 2.6 million years ago. Now, a study funded by the Swiss National Science Foundation (SNSF) suggests that the process may have been present much earlier in some mammals. The results have been published in the Journal of Systematic Paleontology.

https://phys.org/news/2021-04-dormice-hibernated-early-million-years.html

https://www.tandfonline.com/doi/full/10.1080/14772019.2021.1888814