While digging in his field on Monday, Michigan farmer James Bristle found what he thought was ordinary debris in his field. After digging further, he discovered that what he had found wasn’t a fence post, but bones from a Woolly Mammoth.

After the discovery, Bristle contacted the University of Michigan, who arrived to excavate the skeleton, according to Ann Arbor News. According to Daniel Fisher, the director of the Museum of Paleontology at the University, the animal was “an adult male, probably in its forties at the time of its death, probably lived between 10,000 and 15,000 years ago.”

Mammoth fossil unearthed

He went on to say that the animal skeleton was incomplete and discovered in what had been a pond: their hypothesis is the mammoth was partially eaten and stored for later. There’s evidence of human activity: stone tools were found on the site, the way the animal’s bones were discovered, and three boulders found next to each other, which they think was used to anchor the remains in place.

This was also a rare find: According to the University of Michigan, over 300 mastodons have been uncovered over the years in the state, but in the same time, only 30 woolly mammoths have been recovered. Moreover, this one was particularly complete, even as it was missing some pieces.

Bristle discovered the fossil while excavating the land for a lift station for a natural gas line, and gave the excavation team a day to complete their work. The fossil has since been recovered and will now undergo further study.