October 25, 2014

Work continues on dig to uncover mammoth in Mahaska County

Work continues at an undisclosed site in south-centeral Iowa’s Mahaska County where scientists are excavating the fossilized remains of a mammoth. Retired University of Iowa geoscience professor, Holmes Semken, says a local fossil hunter discovered a large bone that turn out to be part of the mammoth.

The man, who is identified only as John, called in the U-I experts to help uncover more of the large beast. “He had a femur, a tibia, part of a scapula and a rib. And with that combination, you know there’s a lot of mammoth together, and that got our interest,” Semken says.

“He didn’t find it on a sandbar, which is good for us, because we’re mostly interested in the context in which the bones came.” Semken says all the things in the soil around the bones are important information keys on the history of the animal.

“There are logs, ice-age logs preserved in the deposit, there are ice-age seeds, this also means there’s ice-age pollen,” Semken explains. He says the logs, seeds and pollen all give scientists a picture of the environment that the animal lived in. Finding a mammoth bone in Iowa is not unusual, but this case of multiple bones found in soil is unique.

“It’s unusual to find a specimen like this, with a willing landowner that has all of its documentation with it. We’re sort of interested in the bones — we’ll we are interested in the bones — we’re more interested in how it died, but we’re more interested in how it lived. These databases associated with the find are really quite exciting,” Semken says.

The scientists have been working with the owner of the site since he called them in and are being careful to uncover all the information that’s available. Semken says they’ve taken dirt core samples of the site and used ground-penetrating radar to try and get an idea of what’s in the area below the surface of the dig.

“Because we just don’t want to dig down with a backhoe or something like that and ruin a bison bone bed that might be inbetween. So, we’re going at this with reasonable patience, and that means shovels instead of backhoes,” Semken explains. The discovery of a complete Tyrannasourus Rex skeleton several years ago in the Dakotas led to lawsuits and legal fights over the bones that were later named Sue and now reside in a museum in Chicago.

Semken says this find is different as this mammoth is on private property, so there’s no question who owns it. Semken says with Sue there were questions about whether it is owned by native Americans, the federal government of the people who found it.

The owner kept quiet about the discovery for almost two years after finding it, and then decided he needed help with the recovery and called in Semken and the others. Semken says they take precautions to protect the site, but the identity and location have been kept pretty secret except for one slip when a television crew did a story on the find.

“A picture of the owner’s house got in the footage, and all of a sudden it was all over facebook in the Oskaloosa area and people were trying to figure out where it was, and we’re sure some did. But we are leaving enough dirt over anything that we can’t collect during the dig, that’s six feet, nobody’s going to shovel down to that and steal any bones. And you have to go behind the house in order to get there,” Semken says.

Semken says it’s exciting that farmer who found the bones is sharing the experience with scientists. He says local conservation officers will help with the dig as will some college students from William Penn in Oskaloosa.