A woman taking a weekend walk on a beach in California found something unusual sticking out of the sand: a tooth from an ancient mastodon.
But then the fossil vanished and it took a media blitz and a kind-hearted jogger to find it again.
Jennifer Schuh found the foot-long (.30-metre) tooth sticking out of the sand on Friday at the mouth of Aptos Creek on Rio Del Mar State Beach, located off Monterey Bay in Santa Cruz County on California’s central coast.
“I was on one side of the creek and this lady was talking to me on the other side and she said ‘What’s that at your feet’,” Ms Schuh recounted.
“It looked kind of weird, like burnt almost.”
Ms Schuh was not sure what she had found.
So she took some photos and posted them on Facebook, asking for help.
The answer came from Wayne Thompson, palaeontology collections adviser for the Santa Cruz Museum of Natural History.
Mr Thompson determined that the object was a worn molar from an adult Pacific mastodon, an extinct elephant-like species.
“This is an extremely important find,” Mr Thompson wrote, and he urged Ms Schuh to call him.
But when they went back to the beach, the tooth was gone.
A weekend search failed to find it.
Mr Thompson then sent out a social media request for help in finding the artefact.
The plea made international headlines.
On Tuesday, Jim Smith of nearby Aptos called the museum.
“I was so excited to get that call,” said Liz Broughton, the museum’s visitor experience manager.
“Jim told us that he had stumbled upon it during one of his regular jogs along the beach, but wasn’t sure of what he had found until he saw a picture of the tooth on the news.”
Mr Smith donated the tooth to the museum, where it will be on display from Friday until Sunday.
The age of the tooth is not clear.
A museum blog says mastodons generally roamed California from about five million to 10,000 years ago.
“We can safely say this specimen would be less than one million years old, which is relatively ‘new’ by fossil standards,” Ms Broughton said in an email.
Ms Broughton said it is common for winter storms to uncover fossils in the region and it may have washed down to the ocean from higher up.
Ms Schuh said she is thrilled that her find could help unlock ancient secrets about the peaceful beach area.
She did not keep the tooth, but she did hop on Amazon and order herself a replica mastodon tooth necklace.
“You don’t often get to touch something from history,” Ms Schuh said.
It is only the third find of a locally recorded mastodon fossil.
The museum also has another tooth along with a skull that was found by a teenager in 1980.
It was found in the same Aptos Creek that empties into the ocean.
“We are thrilled about this exciting discovery and the implications it holds for our understanding of ancient life in our region,” museum executive director Felicia B Van Stolk said in a statement.
