|Fear is an acceptable response.|
When we think of oversized anything in the animal kingdom we tend to think that the only place to look is in the fossil record. That is, after all, where we find giant sloths, oversized wolves, dinosaurs, and enormous terror birds. We know that they are fantastic digging animals and spend a lot of time, including hibernation in a burrow. Was there, then, an even more giant ground squirrel that burrowed extensively in the history of life? Fossilized burrows are known from much earlier than the current era. The first burrows belong to very early animals, but if we are looking for the recent ancestors of giant squirrels, we do not need to go that far back.
|Photo of Clarkia, Idaho squirrel fossil by |
Bill Richards, North Idaho College
The first ground squirrels appear shortly after the Eocene, in the early Oligocene, at approximately 30 million years ago in Europe. As far as the marmots themselves, there is no clear consensus on when this large group of ground squirrels first appear in the fossil record. They are evident by the Late Oligocene in North America. It is acknowledged that by the time we have a good fossil record, in the Mid-Miocene, the ground squirrels, particularly prairie dogs, are already well-represented within their modern range. The fact that we recognize their fossils as highly similar to their extant morphology does not really bode well for finding the origins of Punxsutawney Phil and Gus' family though. Truly, the fact of the matter is that squirrels, as long as we have known them in the extinct and extant capacity, have looked pretty much like squirrels. One could almost say that rodents are kind of like the cockroach of the mammal family in that they have existed long enough to have "survived anything and everything" that life can throw at them. We may see if this remains true in our own lifetimes, but let us hope that we do not.
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