A new fossil find represents the earliest record of living beavers in North America, the Bureau of Land Management reports.
BLM staffers found a pair of teeth on BLM land near Dayville in Grant County during the course of their normal duties., the federal agency said in a statement from Portland.
These teeth come from the Rattlesnake Formation and are 7 to 7.3 million years old.
Worldwide, the earliest "true" beaver, as we would think of them today, comes from Germany, about 10 to 12 million years ago, the BLM explained. These animals then spread across Asia, and eventually crossed the Bering Land Bridge to North America.
The new find helps resolve when beavers dispersed to North America from Asia, and when the two living species, the North American Castor canadensis and Eurasian Castor fiber, diverged.
Previously, the earliest known records of living beavers in North America were from Nebraska, California, and northern Oregon, and date from around 5 million years ago.
"It is fitting that the earliest modern beavers are found in Oregon, since Oregon is the Beaver State; the beaver is the Oregon State animal, and the mascot of Oregon State University," the BLM declared.
The specimens will be going on display in the Thomas Condon Paleontology Center at John Day Fossil Beds National Monument. The new find is described in an article appearing in the current issue of the Journal of Paleontology.
The fossil teeth found near Dayville are almost identical to living beaver teeth, showing that the animal has changed very little in the last 7 million years. This indicates that their appearance and role in the environment would have been the same in the past.
John Day Fossil Beds National Monument includes many of the best studied sites, but the vast majority of fossil localities, including the one with these beaver fossils, are found on adjacent Bureau of Land Management-administered lands.
The National Park Service and the Bureau of Land Management have co-managed fossil resources in eastern Oregon under an agreement for 25 years, which has resulted in the John Day basin being regarded as one of the most important outdoor laboratories for understanding biological evolution and climate change over the past 40 million years.
"New finds like this occur regularly, highlighting the importance of preserving fossils on public lands, which aids scientific research and allows the public to enjoy these valuable natural resources," the agency said.