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University of Iowa News Release


Sept. 23, 2008

Sept. 24 update: This event has been postponed.

Museum of Natural History will host sloth dig events in Shenandoah Oct. 4

The University of Iowa Museum of Natural History will bring the Ice Age to life in Shenandoah, Iowa, on Saturday, Oct. 4, with a day of free public activities exploring the nearby Tarkio Valley sloth excavations.

The day's events, which will be held from 10 a.m. to 4 p.m. at the Greater Shenandoah Historical Society Museum, 405 West Sheridan Ave., include an "artifact road show" where visitors can bring fossils and artifacts to an expert for identification (no appraisals will be given), a display of bones from the excavations, a video showing footage from the site, a slide show on the history and future of the Tarkio Valley, and a hands-on activity table for children.

The Tarkio Valley Sloth Project -- an ongoing excavation of three giant Ice Age sloths -- was recently awarded $20,000 by the National Science Foundation to complete excavation and begin more wide-ranging research on the discovery. The venture began in 2001 when Bob and Sonia Athen uncovered a giant Ice Age sloth, Megalonyx Jeffersoni, in the bed of the West Tarkio Creek behind their home near Shenandoah. Soon, more bones were found on the property of the adjoining landowners, Dean and Loreta Tiemann. Both the Athens and the Tiemanns graciously agreed to permit excavation and donate the fossils of this rare species to the UI.

Megalonyx Jeffersoni, an elephant-sized Ice Age beast, lived in Iowa for thousands of years before its extinction about 12,000 years ago. Only six semi-complete skeletons of this species have ever been found. To date, the Tarkio Valley adult is the second most-complete skeleton of its kind: more than 100 bones have been recovered from the site. In 2006 two juvenile Megalonyx Jeffersoni were discovered near the adult sloth, making the site the first of its kind. Project leader Holmes Semken, emeritus professor in the UI Department of Geoscience, said this is the first time any juvenile -- much less two -- has been found directly associated with an adult. The older juvenile is also the second most complete juvenile of its kind ever found, with more than 40 bones recovered. The skeletons have the added research benefit of being buried in sediments that will provide valuable environmental data about the climate during the sloths' lives.

The Tarkio Valley Sloth Project is a joint effort between the UI Museum of Natural History, Department of Geoscience and Office of the State Archaeologist with volunteers and students from across the Midwest. Other groups that have participated in excavation and research include: the Page County community, the Iowa Archaeological Society, the Mid-American Paleontological Society, the Boy Scouts of America's Mid-Iowa Council, the Iowa Academy of Science, and staff and students from educational institutions all across Iowa. The project has also received assistance from the U.S. Department of Agriculture, the U.S. Army Corps of Engineers, the U.S Geological Survey and the National Park Service.

For more information or a schedule of Shenandoah events, please call the Greater Shenandoah Historical Society Museum at 712-246-1669. For more information on the Museum of Natural History, please visit or call (319) 335-0480.

STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500

MEDIA CONTACTS: Sarah Horgen, UI Museum of Natural History,, 319-335-0606; George McCrory, University News Services, 319-384-0012,