Bones uncovered in southwest Iowa in 2002 are now being examined by University of Iowa researchers who are hoping to learn more about what Iowa was like during the Ice Ages. It all started when Bob and Sonya Athen spotted an unusual bone in a creek bed behind their home near Shenandoah.

The Athens brought the bone to Iowa City during a visit with their daughter who attends the U-I. Geology professor Holmes Semken determined the bone was from a Jefferson Ground Sloth, which have been extinct for 10,000 years. “I stepped through the door, saw that thigh bone and I knew right away that this was an extinct giant Ground Sloth,” Semken said. “I knew there was more there because she had three other bones with her, which included ribs and vertibre from the neck and tail. It looked like a complete specimen.”

The University of Iowa’s David Brenzel and others spent eight years digging around the site near Shenandoah. Brenzel says the Ground Sloth was an impressive creature. He says the typical Ground Sloth was 10 feet tall and weighed about 3,000 pounds. The animal also had long arms with “imposing claws” to reach into trees.

Sarah Horgan, who coordinates the University of Iowa’s Museum of Natural History, says the dig produced 104 adult Sloth bones, 41 bones from a juvenile Sloth and a shoulder bone from a baby. A Canadian researcher is now analyzing DNA to determine if they’re a family.

“The number of bones that we’ve recovered and the number of animals at the site…we have an adult and two juvenile Giant Sloths, and that’s unheard of…there’s no other site to compare this to,” Horgan said.

“So, scientifically, this is in a league of its own.” The Shenendoah discovery produced one of only 200 specimens of Giant Sloth bones known in North America.