What began as a casual walk to hunt for arrowheads turned into one of the most important paleontological discoveries in Iowa in decades.

A teenager, whose name has not been disclosed, was exploring a friend’s private farmland near a creek when he noticed something large and unusual jutting out from the soil. What he initially thought might be a rock turned out to be the jawbone of a juvenile mastodon — a prehistoric cousin of the elephant that roamed North America tens of thousands of years ago.

The jawbone, measuring 30 inches in length, is believed to be around 34,000 years old, and scientists say the fossil was found just in time. If it had remained exposed for a few more days, the delicate bone would likely have dried out in the sun and crumbled into dust.

A Prehistoric Surprise on the Plains

The teen was walking near a creek on the property when he spotted the large, heavy fossilized bone. According to Tiffany Adrain, special collections manager at the University of Iowa’s Paleontology Repository, the teen cradled the bone in his arms and carried it back to the farmhouse.

“The landowners already knew what to do,” said Adrain in an interview with VICE. “They wrapped it up in plastic to keep it wet and sent us an email right away.”

The jawbone, incredibly well preserved, was likely buried until very recently. Experts believe recent weather or erosion might have dislodged it from the soil and exposed it — briefly — to open air.

“We were incredibly lucky,” Adrain emphasized. “This fossil hadn’t been exposed for long. It’s a miracle find.”

Now secured in the university’s Trowbridge Hall, the jaw has been cataloged, kept moist, and stored away with other rare fossil specimens.

What Is a Mastodon, Exactly?

Mastodons are often confused with woolly mammoths, but they’re a distinct species with a longer evolutionary lineage and different dietary habits.

• Scientific Name: Mammut americanum

• Lived: ~27 million to 10,000 years ago

• Habitat: Forested regions of North and Central America

• Size: Adult males could reach 9+ feet in height with 16-foot tusks

• Diet: Browsers — fed primarily on leaves, twigs, and shrubs

Unlike mammoths, which were grazers adapted to cold tundra climates, mastodons were more at home in woodlands and wetlands, much like the Iowa farmland where this jawbone surfaced.

Their extinction around 10,000 years ago is thought to have been caused by a mix of climate change and overhunting by early human populations.

A Fossil Saved in the Nick of Time

The biggest risk after such a find isn’t theft — it’s nature itself. Fossils that are exposed to the sun and air after millennia underground can rapidly dry out, causing them to fracture, flake, or simply disintegrate.

Thanks to quick action by both the teen and the landowners, the jawbone was kept hydrated and properly transferred to paleontologists. The university team is now preserving the specimen with plans to scan, study, and possibly display it.

“It’s still very much a bone,” said Adrain. “It hasn’t fully fossilized into stone, which is part of why it’s so fragile — and so fascinating.”

Not Their First Fossil Rodeo

Incredibly, this isn’t the first time the landowners have had a brush with the Ice Age.

Roughly 30 years ago, they reportedly uncovered other mastodon remains while fishing on the same property, though those earlier finds were not as complete. The family has chosen to remain anonymous to discourage fossil hunters from trespassing or damaging the land in search of buried prehistoric treasures.

Iowa: A Graveyard of Giants

Long before cornfields and tractors, prehistoric Iowa was a diverse and thriving ecosystem filled with megafauna.

Fossils found across the state have included:

• Giant beavers the size of black bears

• Short-faced bears with powerful limbs and huge jaws

• Ground sloths the size of small cars

• Ancient camels and horses

• Giant bison roaming in herds across open plains

Mastodon bones are among the more dramatic finds — not just because of their size, but because of what they reveal about the region’s past. Each discovery offers a new clue about how early ecosystems functioned and what may have led to their collapse.

What’s Next for the Jawbone?

While the fossil will not be on public display immediately, researchers say the teenage discoverer may be invited to assist or visit the lab as scientists begin cleaning and analyzing the jaw.

Adrain and her colleagues plan to conduct CT scans and isotopic analysis to determine more about the animal’s age, diet, and even the season of its death.

“This was a young mastodon, maybe about seven feet tall,” said Adrain. “It’s possible the rest of the skeleton is still nearby — and if it is, that would be an extraordinary discovery.”

For now, the find serves as both a scientific windfall and a reminder that beneath Iowa’s modern agricultural fields lies a forgotten wilderness, filled with stories from an Earth that existed before human memory.