THE ASTEROID-IN-SPRING HYPOTHESIS

It took ten days for two young paleontologists to turn on each other, each claiming to have found new evidence of the worst day in the history of life on Earth.

- KERRY HOWLEY

IN AUGUST 2017, a bubbly Dutch pink-haired 28-year-old graduate student flew from Amsterdam to South Dakota, where empty fields rolled wide before her, towns of a hundred people and a single church.

"You a celebrity or somethin'?" a man had said last time she was in the area, picking up a can of Monster at a truck stop. "Not to my knowledge," she said.

Melanie During had never been to New York, or Los Angeles, or Chicago, but she was already familiar with this particular landscape, dense with buried bone. Also in town was a 70-year-old Dutch paleontologist named Jan Smit, a man she got to know the day she dissected an ostrich in his kitchen.

With him was a stranger, a 35-year-old American graduate student. The three of them drove to what During casually calls "a triceratops mass grave," at which point, to her surprise, Smit left. For the next few days, it would be the two students and whatever the ground gave up. Her companion drove a 4Runner under the arc of a giant sky feathered with clouds, through panoramic prairie, fields of buffalo, mud buttes rising against the horizon. He pulled off a gravel road and right onto a ranch.

They got out of the truck. With each step, dry grass crunched under their feet and grasshoppers sprang in all directions. Through the knee-high thistle, it was hard to judge where each footfall would land. The grass stopped, and the earth dipped into a gnarled mass of rock and clay. The land was strange, full of odd textures, scaly in spots, darkly reptilian, and blanched out in others. He was proud of the place. While the site was not technically his property, it was spiritually his, shaped and carved and loved by him, and During was there with his permission. He called it Tanis, so everyone else did too.