Woman Discovers Tooth of Extinct Mammal on Oregon Coast

A tooth of an extinct mammal, possibly dating back to around 20 million years ago, was discovered on the coast of Oregon.

The tooth was spotted on March 25 by Amariah Jacobs, a preschool teacher, who found it “on the Oregon coast while walking the beaches looking for agates (stones made from volcanic and metamorphic rocks),” she told Newsweek.

Jacobs said the fossil was identified as a Desmostylus hesperus tooth by a curator at the Smithsonian museum, whom she contacted after she was “stunned” by her discovery.

Newsweek reached out to the Smithsonian for comment.

Jacobs’ husband shared viral images of the tooth on Reddit under his username u/randumbum. Since March 25, the post has had 11,000 upvotes.

Desmostylus hesperus tooth in Oregon.
Images of the Desmostylus hesperus tooth discovered by Amariah Jacobs. She said she initially thought it could be a cluster of slipper snails.

Amariah Jacobs

Jacobs noted that the latest find “is not a hippo, but a predecessor,” adding that “20 million years old is a very reasonable estimate on age [of the tooth] based on prior finds on record and the region where I was walking.”

Desmostylus hesperus is a species of extinct hippopotamus-like marine mammal from the Desmostylia order.

Desmostylia are herbivorous marine mammals that have been “enigmatic since their discovery because of their unusual skeletal and dental morphologies…” according to a June 2023 study in Royal Society Open Science.

“Their fossil remains have been found in Oligocene and Miocene strata across the North Pacific Rim,” the study notes.

The Oligocene is a geologic period that lasted from around 33.9 million to 23 million years ago, while the Miocene is a period that lasted from around 23 million to 5.3 million years ago.

The study says that “the distinctive tooth morphology of Desmostylus has persisted, largely unchanged, for more than 15 million years and that desmostylids [a family within the Desmostylia order] possibly originated in western North America.

“Occurrences of the genus Desmostylus are almost entirely limited to middle Miocene strata, with only a few early Miocene records from Japan,” researchers wrote.

Desmostylus hesperus tooth in Oregon.
The Desmostylus hesperus tooth found on the Oregon coast. Johnson saw the jawbone on a “small patch of gravel among miles of sand.”

Amariah Jacobs

‘Stunned Silent’

Jacobs told Newsweek that she and her husband drive from the Willamette Valley in Oregon to the coastline where they “hike and rockbound four to 10 miles, weekly.”

On the day of her latest finding, she recalled seeing “the jawbone on a small patch of gravel among miles of sand.”

“From a distance, I thought the teeth might be slipper snails in a typical cluster. When I got closer, I could recognize fossilized mammal bone,” she said.

“By the time I picked it up my own hands were trembling, and I felt stunned silent. About an hour later I told my husband, ‘I think I found something really good this time,'” she added.

Jacobs is a Reggio Amelia-inspired teacher. The approach is an educational philosophy that originated in Reggio Emilia, a city in northern Italy, that emphasizes providing children with a “creative, collaborative, and expressive” education, according to the Early Childhood Intervention Professional Development Center at Georgetown University.

“When my students want to become geologists, I become a geologist, and when my students want to become paleontologists, I become a paleontologist to assist in their studies,” Jacobs said.

The teacher said her latest specimen finding has been offered to the University of Oregon to form part of their paleontology collection but has yet to hear back from the school.

Do you have a travel-related video or story to share? Let us know via and your story could be featured on Newsweek.