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Where did the earliest known rodent fossils occur?
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rodent
Black-tailed prairie dog (Cynomys ludovicianus).
The earliest known fossil rodents belong to the extinct families Alagomyidae and Ischyromyidae, which are classified within the suborder Sciuromorpha. While the documented evolutionary history of rodents extends back 56 million years to the Late Paleocene Epoch in North America, these species are believed to have originated in Eurasia. Because there is a lack of fossil evidence prior to the Late Paleocene, the exact timing and location of the origin of the order Rodentia remain a subject of ongoing scientific study.1