WESTERLY — Under the hot, dry North Dakota sun, Alison Diffin stumbled upon undiscovered, fossilized leaves.

Her unexpected find is expected to help shed light on what the climate was like shortly after the extinction of the dinosaurs that roamed there 65 million years ago.

“I had no idea,” said the Westerly 17-year-old.

Diffin spent two and a half weeks this summer in the Badlands of southwest North Dakota assisting University of Rhode Island geosciences master’s student Rachel Grandpre, whose thesis deals with the aftermath of the extinction of dinosaurs.

“I loved it. I want to go back,” Diffin said of the experience.

Grandpre is a student of David Fastovsky, a professor of geosciences at URI. Fastovsky’s wife, Lesley, taught chemistry to Diffin at Westerly High School last year during her junior year.

So when Lesley Fastovsky asked Diffin if she would be interested in pitching in as a research field assistant, the teen said she jumped at the opportunity.

“Digging things up in the middle of nowhere, driving cross country? That sounds fantastic,” she enthused.

After driving cross-country with Grandpre, Diffin spent long days that began at 6 a.m. digging into Pretty Butte, a 3,000-foot isolated hill with steep sides, located just north of Marmarth.

“I was the muscle, if you can believe it,” said the petite Diffin.

She described climbing and creating her own foot holes in the loose, steep slope of the butte, roughly two building stories up, as “terrifyingly dangerous” at times. Layers of clay would stick to her shoes, while cacti and naturally formed brick pieces lay below.

The butte clearly showed the different sediment layers, including what is called the K-T Boundary, a line marking the extinction of the dinosaurs.

“It’s really interesting and it becomes very addicting and very satisfying,” Diffin said of the dig, completed with a hoe pick.

While taking a break one particularly hot day, Diffin said she began picking apart pieces of fragile slate-like rock. The rocks contained fossilized leaves.

Diffin said she was surprised when Dean Pearson, a well-known paleontologist working in the area, said the leaves were an important and previously undiscovered find.

Lesley Fastovsky said the site filled with 64-million-year-old fossil leaves will add another piece to the puzzle that paleontologists use to reconstruct what the earliest environments looked like after the dinosaurs went extinct.

Diffin said she plans to make the leaf site the topic of her senior project, required by the state and Westerly High School to graduate.

Diffin plans to graduate early this year, but does not yet know her college plans. She said she expects to pursue paleontology and geology as a hobby, and study psychology in school.

Aside from the leaf site, Diffin said she also discovered a welcoming and friendly small town in Bowman, North Dakota.

“That placed wormed its way into my heart big time,” Diffin said. It is home to the Pioneer Trails Regional Museum, which includes impressive paleontology archives.

Dinosaur bones are plentiful in North Dakota and Montana’s Hell Creek Formation. Diffin said she stumbled upon a Triceratops skeleton and, with Grandpre, part of a Tyrannosaurus Rex bone.

“I was just so shocked,” she said of spotting dinosaur remains. “… I’m walking past this and it’s a dinosaur. What the heck?”

Dinosaur bones are differentiated from rocks by licking them, she learned, because ridges and pores in the bones suction to a moist tongue.

“That whole area is… a smorgasbord of dinosaur creatures,” she said. “At the least, you’ll find a [fossilized plant] reed.”

Over the course of the dig, Diffin also saw dinosaur teeth, petrified wood, tortoise shell fragments and myriad animals native to the prairie and grasslands. She spotted scorpions, rattlesnakes, flying red ants, droves of antelope, herds of Buffalo, mule and white-tailed deer, elk, wild horses and prairie dog towns.

“It’s absolutely, breathtakingly beautiful,” Diffin said of the countryside.

The vistas made up for returning to the campsite at the end of the day with clothing permanently stained, Diffin’s face black and her legs red and brown from the layers of sand, coal and clay.

“I think camp showering should be an Olympic sport,” she said, adding the hard water did little to remove the filth.

But Diffin said she loved sleeping outdoors under a “huge amphitheater” night sky, and witnessing rainstorms that evaporated before hitting the hot ground, lightning and evening clouds formed by the collision of hot and cold air.

“It was like, I don’t know, a Michelangelo painting,” she said.

edupuis@thewesterlysun.com