Earliest North American Beaver Thought To Have Sharpened Teeth Near Site Of Today's John Day Fossil Beds National Monument
It might not look so good to a beaver these days, but once upon a time the landscape in and around today's John Day Fossil Beds National Monument kept beavers happy.
Researchers at the Oregon-based monument working with U.S. Bureau of Land Management partners have unearthed fossilized teeth that represent the earliest record of living beavers (Castor) in North America.
A pair of teeth was found on BLM land near Dayville, Oregon, just a very small handful of miles from the monument's Sheep Rock unit. That discovery is a result of an ongoing partnership between the BLM and the Park Service allowing for the cooperative management and protection of eastern Oregon's paleontological resources.
These teeth come from the Rattlesnake Formation and are between 7 and 7.3 million years old, according to a Park Service news release.
Worldwide, the earliest "true" beaver, as we would think of them today, comes from Germany, about 10 to 12 million years ago, the Park Service notes. "These beavers then spread across Asia, and eventually crossed the Bering Land Bridge to North America," an NPS release adds.
The discovery 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 around 5 million years old, according to Park Service researchers, who say it is only 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 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 are almost identical to living beaver teeth, showing that the animal has changed very little in the last 7 million years, according to the researchers, who add that "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 BLM-administered lands. The Park Service and BLM 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.