The Smithsonian.com has a post about the extinction of 7 foot tall beavers.  Up until just over 10,000 years ago, large beavers weighting upwards of 220 pounds roamed a large part of North America, from Alaska and Canada to Florida.  A new study, by a group of Canadian researchers, was published in the journal Scientific Reports.  It posits that these giant rodents went extinct when their habitat became increasing dry and warm at the end of the last ice age about 10,000 years ago.

Yukon News‘ Hong reports that scientists believe the giant beaver migrated from what is now the continental United States to Canada and Alaska around 100,000 years ago. The species thrived in verdant mixed-conifer forests intermingled with plant-filled wetlands for many millennia, but began to suffer the ill effects of Earth’s drier climate beginning 25,000 years ago. At first, local populations vanished mainly from northern territories, but by 10,000 to 11,000 years ago—only one beaver enclave, found in the surrounding Great Lakes region—remained.

Writing for the Conversation, Plint explains that giant beavers—distinguished from their smaller modern counterparts by bulkier curved incisors and an elongated rather than paddle-shaped tail—failed to adapt to the continent’s changing climate largely because of their overdependence on wetland habitats.

Today, modern beavers, which actually co-existed alongside giant ones for tens of thousands of years, were able to use their sharp-edged teeth to cut down and eat trees, build lodges and dams, and essentially shape the landscape to suit their needs. Ancient mega-sized ones, however, found themselves ill-equipped to seek out new habitats and food sources.