A rare find

A rare find

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UI-led crew says newly found scapula belongs to third mammoth
mammoth tusk being wheeled into the museumJohn Porter, Holmes Semken, Sarah Horgen, and David Brenzel help deliver a mammoth tusk to campus. To date, a UI-led research team has uncovered more than 100 bones from what it thought was two mammoths. A scapula recently uncovered indicates there is likely a third mammoth at the dig site in southern Iowa. Photo by Bill Adams.

A University of Iowa-led team announced today that it has located a third mammoth at a dig site in southern Iowa.

The find comes from a scapula uncovered in early December by researchers with the UI's Museum of Natural History. The scapula is the latest in a string of discoveries including a tusk, a section of a skull, ribs, and leg bones. After cleaning the scapula and measuring it, the paleontologists realized that it was larger than other scapula previously unearthed at the dig and thus must belong to a third mammoth. The team thinks it's likely the third mammoth is also a woolly species, although more bones will need to be analyzed to confirm.

What the researchers do know is finding three mammoths at one place is rare.

"For Iowa, this is a first," says Sarah Horgen, the museum’s education and outreach coordinator. "And, for the Midwest, there are very few sites that have three or more animals."

The research team has been working on the mammoth dig since April 2012. Related stories:

Discovery of mammoth proportions

Two mammoths are better than one

Woolly mammoth found at Iowa site

The news punctuates a busier-than-expected wintertime break in the much-publicized search for the remains of mammoths that once roamed Iowa. Since April, the UI museum has led the mammoths’ excavation on a private property near Oskaloosa. To date, the team has uncovered more than 100 bones—from femurs to tusks to teeth—from three specimens. The group also has collected plant and soil residue at the site to learn more about the environment in which these beasts lived when they tromped around the Iowa landscape during the last Ice Age some 14,000 years ago.

“This project has already exceeded our early expectations in the amount of evidence uncovered at the site as well as the incredible educational experiences we have been able to offer Iowans of all ages who are participating in various aspects of the project,” Horgen says.

Before the latest discovery of a third mammoth, investigators believed they had found one woolly mammoth and one Columbian—a related species that is larger than a woolly—a theory based mostly on the size of a femur and a scapula uncovered earlier in the dig. But then the paleontologists came up with a well-preserved tooth and a four-foot slab of tusk that threw the Columbian mammoth theory into doubt. Now the group believes at least two of the beasts are woolly mammoths, including a super-sized, middle-aged male who was about 40 years old when he died.

Chris Widga of the Illinois State Museum has worked with the UI-led team to identify the mammoth remains. Widga thinks the discovery of a larger-than-expected woolly, along with a few past woolly mammoth finds in the Midwest, may cause paleontologists to alter the perception of the size of those mammoths that lived in the region.

“Woolly mammoths are not as common in Iowa as their relatives, the Columbian mammoth, so the discovery of possibly three is pretty exciting,” says Holmes Semken, a UI professor emeritus in geoscience who has worked closely with Horgen on the dig.

Not much is known about the environmental conditions in Iowa during the last Ice Age. Botanical remains can yield clues about the climate and landscape during this time period as well as what the animals were eating. Faculty and students from the Department of Geosciencein the UI College of Liberal Arts and Sciences are currently examining plant remains uncovered near the bones as well as looking for pollen grains recovered in soil cores taken around the site to learn more about the ecology of Iowa while these animals were alive.

One of the most exciting discoveries so far is the tusk. The fragment, along with other mammoth bones, is being cleaned and stabilized at the museum. For students and faculty alike, it’s a rare opportunity to examine ancient animal history up close and personal.

mammoth bone being cleaned
Undergraduate student Brianna Pickel cleans what is believed to be a tibia. Photo by Bill Adams.

“I never thought I would have the chance to clean mammoth bones, and have hands-on experience with the ancient fossils,” says Kristin Tefft, a UI sophomore from Dubuque, Iowa, majoring in biochemistry. Tefft is one of a half-dozen UI undergraduates working on the mammoth project.

“The process is very delicate. You have to clean the bones very gently with small brushes, making sure to keep any fragments that may flake off,” says Aaron Last, a sophomore from West Liberty, Iowa, who is majoring in geoscience and works at the museum.

The amount of work and research on the recovered bones will keep museum staff and volunteers busy during the dig hiatus. The first order of business will be to finish cleaning the bones and stabilizing others by gluing fragments together and building support structures to store them safely. The group aims to compile an inventory of the remains, with measurements and photographs of the individual bones.

The crew is reasonably confident that more bones are yet to be found
—perhaps enough to form nearly complete skeletons for the beasts. That’s because workers already have found both large and small bones, a good sign that the area has been little disturbed by nature or scavengers. Researchers are also beginning work on combining GPS data with hand drawn maps and photos from each excavation to create a complete site map. All these tasks will keep volunteers busy indoors.

To date, more than 150 people of all ages from across Iowa and beyond have participated in the excavation and laboratory research. Wishes for an early spring bolster hopes of getting back to the bones they know are still in the ground.

“The landowner is beyond pleased with everything that has been uncovered so far but we all joke that a saber-toothed cat would be an exciting addition to the mix,” Horgen says.


Sarah Horgen, Museum of Natural History, 319-335-0606
Miles Dietz, Museum of Natural History, 563-299-8397


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