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When do the earliest known rodent fossils date from?
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rodent
Black-tailed prairie dog (Cynomys ludovicianus).
The evolutionary history of rodents is documented by fossils dating back 56 million years to the Late Paleocene Epoch in North America.1
While these North American fossils represent the earliest known records, specialists believe the order Rodentia originated in Eurasia and is therefore older than the current fossil evidence suggests. The extinct families Alagomyidae and Ischyromyidae, which belong to the suborder Sciuromorpha, include the earliest-known fossil rodents.1