This video is called BEAVER slap, mate build, swim, lodge.
From Oregon Live in the USA:
September, 24 2011
If there was any doubt, a new find cements Oregon’s distinction as the Beaver State.
The molar and premolar — back teeth — were below an ash layer from an ancient volcanic explosion that scientists say dates to about 7 million to 7.3 million years ago.
“This tells us they are older than that eruption,” said Joshua Samuels, museum curator and chief of paleontology at the monument.
Until now, the earliest beavers in North America dated to around 5 million years ago, he said Monday.
The find is significant because it helps pin down the time when beavers crossed the Siberian land bridge from Asia, Samuels said. Scientists believe they migrated to Asia from Germany, where older beaver fossils date to 10 million to 12 million years ago.
Only the enamel remains of the 1 1/2 -inch-long teeth discovered here. The rest of the teeth turned into stone. They belonged to an adult animal and appear worn, but it’s hard to say more about the beaver’s age, Samuels said.
In the flesh, it would be indistinguishable from a modern beaver. The animals haven’t changed much in the last 10 million years in contrast to Homo sapiens, which scientists say are only about 200,000 years old.
Because the beaver anatomy is essentially the same, “we can interpret that their lifestyle was the same. They cut down trees and built dams, just like beaver today,” Samuels said.
The climate then also is believed to have been roughly identical to today’s, with sagebrush, bunchgrass and oak-shaded rivers, he said.
John Zancanella, coordinator of the U.S. Bureau of Land Management‘s paleontology program in Prineville, discovered the ancient teeth on an eroded, rolling stretch of BLM land.
He wasn’t sure just what he had after picking the teeth off the frozen ground in February 2010. “I knew I had found a rodent and I suspected a beaver, but I didn’t know the importance of that,” he said.
Zancanella turned them over to Samuels, a beaver specialist: “I said, ‘Here, Josh, look what I found. He got pretty excited very quickly.”
The find came from the Rattlesnake Formation, a layer of sediment from an ancient stream overlain by volcanic ash named after nearby Rattlesnake Creek. The formation has produced fossils of canines believed to be the ancestors of coyotes and wolves, fox, pronghorn antelope, rhinos, elephant-like mastodons and small one-toed horses, all nearly identical to modern animals.
The ash that protected the beaver teeth for so many centuries came from “an enormous eruption” of a volcano in the Harney County Basin near Burns, Samuels said. “A lot of eastern Oregon was covered by this single volcanic unit,” he said.
And for those who are wondering: The 1969 Legislature picked the beaver as Oregon’s state animal.
Evolutionary Tree of Life for Mammals Greatly Improved: here.
Ice Age coyotes were supersized compared to coyotes today, fossil study reveals: here.