Detroit Science News Examiner: Mammoth remains

[neonvincent]

Probably my best science story from 2015.

Mammoth remains could be oldest evidence for humans in southeast Michigan

A mammoth whose skeleton was removed from a Washtenaw County field this week may have been butchered by humans, the University of Michigan announced in a press release issued Friday. If the extinct elephant relative remains were indeed cut by humans and found to be older than about 12,000 years old, they could be the oldest evidence for humans in southeast Michigan.

The mammoth bones were recovered from a farm owned by James Bristle in Lima Township near the city of Chelsea, Michigan, about ten miles southwest of Ann Arbor. A team of University of Michigan paleontologists led by Professor Daniel Fisher, along with excavator Jamie Bollinger of Bollinger Sanitation and Excavating in Chelsea, who donated his time, were able to recover about 20 percent of the animal's bones, including the skull and two tusks, numerous vertebrae and ribs, the pelvis, and both shoulder blades.

Fisher described the age of both the site and the animal. "It was an adult male, 40 to 50 years of age, and stood probably 10 feet tall at the shoulder," he told The Detroit News. The animal, likely a woolly mammoth instead of its larger relative the Columbian mammoth, died between 15,000 and 11,700 years ago.

In the University of Michigan press release, Fisher said that the site held "excellent evidence of human activity" associated with the mammoth remains. "We think that humans were here and may have butchered and stashed the meat so that they could come back later for it," he continued.

Fisher listed several pieces of evidence for his hypothesis. First, the neck vertebrae were not scattered randomly, as is normally the case following a natural death, but were arrayed in their correct anatomical sequence, as if someone had "chopped a big chunk out of the body and placed it in the pond for storage," Fisher said in the press release. He sounded more confident when quoted by The Detroit News. “It’s too early to tell how it died but the skeleton showed signs of butchering," Fisher said.

The rocks around the skeleton supported the idea that the mammoth had been butchered. A small stone flake that may have been used as a cutting tool was found next to one of the tusks. Also, three basketball-sized boulders were found next to the remains and could have been used to anchor the mammoth carcass in a pond for storage. Caching mammoth meat in ponds for later use is a strategy that Fisher said he has encountered at other sites in the region.

Confirming the hypothesis will require the bones be cleaned and examined for cut marks The fossil will also need to be dated. If the bones show signs of butchering and are old enough, they could provide the oldest evidence of human habitation of southeast Michigan.

Mammoths are relatively rare finds in Michigan. Over the years, the remains of about 300 mastodons, another extinct relative and 30 mammoths have been recovered in Michigan. "We get one or two calls like this a year, but most of them are mastodons," Fisher said in the press release.

Fisher was alerted to the discovery by farm owner Bristle, who found the remains while he was installing drainage pipe at a low spot in a wheat field surrounded by soybeans. A backhoe digging a trench uncovered a roughly 3-foot-long bone.

"We thought it was a bent fence post. It was covered in mud," Bristle told MLive. "We didn't know what it was, but we knew it was certainly a lot bigger than a cow bone," said Bristle in the press release.

Bristle thought it might have been a rib. It turned out to be part of the mammoth's pelvis.

Bristle said the discovery is both exciting and disruptive. But he said he's confident that he made the right decision.

"When my 5-year-old grandson came over and saw the pelvis, he just stood there with his jaw wide open and stared. He was in awe," Bristle said in the press release. "So I think this was the right thing to do."