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Giant Prehistoric Beaver's Discovery in Wicker Park Gets New Look

By Alisa Hauser | December 10, 2013 9:40am
 The palette, or roof of the mouth, and one of the front tooth incisors belonging to a prehistoric beaver were found in the 1960s during construction of what's now Pritzker School at 2009 W. Schiller St. in Wicker Park.  The discovery was highlighted in a new Channel 11 show, Chicago Time Machine.
Prehistoric beaver from Evolving Planet exhibit at Field Museum of Natural History
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WICKER PARK — An old story — a very, very old story — is getting a new look with the debut of Chicago Time Machine, a local history show on WTTW-Channel 11.

Hosted by Geoffrey Baer, the program explores some of the area's quirkier stories, including the discovery of a prehistoric beaver found during construction in 1960 at what is now Pritzker School at 2009 W. Schiller St. in Wicker Park.

"This beaver was a beast, the largest rodent in North America in the last 2½ million years," says Baer on the program, which debuted last week and can be seen here.

Baer said the beaver was about the size of a bear, had front teeth about 6 inches long and roamed the area about 12,000 years ago.

 Parts of a prehistoric beaver that could have weighed as much as 220 pounds were found in the 1960s during construction of what is now known as Pritzker School.
Parts of a prehistoric beaver that could have weighed as much as 220 pounds were found in the 1960s during construction of what is now known as Pritzker School.
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William Simpson/Field Museum of Natural History (Skull); Alisa Hauser/DNAinfo Chicago (Pritzker School)

During the Ice Age, the Chicago area was home to extensive wetlands before European settlement, according to William Simpson, a fossil vertebrates collections manager at the Field Museum of Natural History, 1400 S. Lake Shore Drive.

The Wicker Park beaver specimens, which include one of the beaver's front teeth, as well as the roof of the beaver's mouth, are in the museum's fossil collection.  A full skeleton of a giant beaver that was found in Indiana has been on display since 2006 in the Evolving Planet exhibition.

Known as Castoroides ohioensis, the giant beaver, which was common in the mid-continent of the United States, particularly in Ohio and New York State, "is not a terribly rare fossil as fossils go, but it's just interesting to find one within the city limits of Chicago and to understand what Chicagoland used to be like," Simpson said.

The other giant beaver bones in the museum's collection were discovered in southern Illinois and parts of Indiana, Simpson said.

In comparison to a modern beaver that weighs 10 to 30 pounds, the prehistoric beaver skeleton on display at the museum is 64 inches long with an estimated weight of 132 to 220 pounds.

Simpson said the beaver — which researchers believe might have lived in wetlands since they are commonly found in peat bog deposits — "would be comparable in size to a really big dog or small black bear."

The teeth of the giant beaver have rounded tips, and strong grooves on the outside surface and "could have bitten a finger off no problem," Simpson said.

But Simpson added, "A modern beaver can give you a pretty wicked bite, too." 

Though Simpson said he is unsure what caused the giant beavers to go extinct, he said they were part of the loss of the North American megafauna after the last Ice Age. There's two main theories about their extinction: destruction of habitat and hunting by humans.

What the giant beavers ate continues to puzzle researchers, though they were "certainly vegetarians," Simpson said.

"It's fascinating to see how different Chicago-land was 10,000 years ago," Simpson said.

Other mysteries between the prehistoric beaver — which roamed Chicago's flat marshes along with Mastodons — and the modern beaver, remain.

"We do not know if the giant beaver had a wide, flattened tail, nor do we know if its feet were webbed. ... We really don't know if their lifestyles were equally different. Did they fell trees, did they live in dens that they made?" Simpson asked.

The giant beaver skeleton is displayed at the museun in a corral with Ice Age fossils from all over the world, including a mammoth; a Mastodon (whose lower jaw was discovered during the construction of the Stevenson Expy.); an Irish Deer with "extreme antlers" from Limerick, Ireland; and a horse from the La Brea Tar Pits in Los Angeles.