A 9-year-old boy didn't realize he found a mammoth fossil in his grandma's backyard until Facebook commenters said it looked like a tooth

• A 9-year-old Oregon boy found a 10,000-year-old mammoth tooth in his grandma's backyard.
• At first, the family thought it was just petrified wood until Facebook friends said it looks like a tooth.
• Archeologists confirmed that the fossil he found in a creek is genuine.

A family in Oregon was stunned when their 9-year-old boy discovered an ancient fossilized mammoth tooth in his grandma's backyard last month.

Jeremiah Longbrake was up to his usual after-school activities in the wooded area behind his grandma's house in southern Oregon in mid-April.

As he scoured the brush for interesting rocks, Longbrake said he was digging around in the creek when he saw something that looked like a plastic container or maybe a piece of petrified wood.

So, out of curiosity, he fished it out with a stick. 

Longbrake had no idea he was holding a fossil at least 10,000 years old, a find first reported in the local News Review newspaper.

He said at first he didn't think it was anything special but decided to bring it back to his grandma's house to show his mom, Megan Johnson. 

"When he first brought it to me, I initially thought it was some sort of petrified wood with like quartz running through it," Johnson told Insider. "And then, I got to look at it, and I'm like, well, I've never seen anything like this before, so this is really different... There's some bendy areas and it kind of weaves through almost like a ribbon candy."

Johnson decided to post pictures of the object on Facebook, hoping that her rock-hound friends would be able to help identify it. But they said it didn't look like wood at all; it seemed like a weird tooth.

Johnson reached out to a handful of archaeologists and paleontologists who confirmed that not only was the strange rock a tooth, it was an ancient mammoth fossil.

Johnson said her son was thrilled when he found out.

"I couldn't keep that thing out of his hands, save for the time he was down in the creek looking for more stuff," she said, laughing. 

"I thought that I could have been walking on a dead mammoth body," Longbrake told Insider. "Or a caveman."

Longbrake isn't sure yet what he wants to do with the tooth — he says he'll probably keep it for a while, and then he might donate it to a museum.

But, he said, he definitely won't let his older brother have it.