He agreed to pay the rancher a certain amount for each season that he worked there. His father, Robert, Sr., practices endodontic surgery in nearby Delray Beach; his great-uncle Anthony, who died in 2005, at the age of a hundred, was a renowned orthopedic surgeon who wrote several standard textbooks on the subject. “And to think—sixty-­six million years later, a stinky monkey is digging it up, trying to figure out what happened.” He added, “If it’s a new species, I’ll name it after you.”When I left Hell Creek, DePalma pressed me on the need for secrecy: I was to tell no one, not even close friends, about what he’d found.

Deciphering what happened on the day of destruction is crucial not only to solving the three-­metre problem but also to explaining our own genesis as a species.On August 5, 2013, I received an e-mail from a graduate student named Robert DePalma. The energy released was more than that of a billion Hiroshima bombs, but the blast looked nothing like a nuclear explosion, with its signature mushroom cloud.

Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere. He showed me a photo of the amber seen through a micro­scope. “If it’s what it’s said to be,” Johnson said, “it’s a fabulous discovery.” But he declared himself “uneasy” until he could see DePalma’s paper.One prominent West Coast paleontologist who is an authority on the KT event told me, “I’m suspicious of the findings. (There are eight other co-authors.) It was immediately apparent to them that the KT tsunami would have arrived too late to capture the falling tektites; the wave would also have been too diminished by its long journey to account for the thirty-­five-foot rise of water at Tanis. “Look at these two fish.” He showed me where the sturgeon’s scutes—the sharp, bony plates on its back—had been forced into the body of the paddlefish. The dinosaur feathers are crazy good, but the burrow makes your head reel.” In paleontology, the term Jan Smit, a paleontologist at Vrije University, in Amsterdam, and a world authority on the KT impact, has been helping DePalma analyze his results, and, like Burnham and Walter Alvarez, he is a co-author of a scientific paper that DePalma is publishing about the site. Later, though, he wondered how the bone, which was heavy, had arrived there, very close to the high-water mark of the flood. “Amber with tektites embedded in it—holy cow! (The specifics of the arrangement, as is standard practice in paleontology, are a closely guarded secret. “I want everything!”He showed me the impression of a round object about two inches wide.

He quietly shared his findings with a half-dozen luminaries in the field of KT studies, including Walter Alvarez, and enlisted their help. The dust and soot from the impact and the conflagrations prevented all sunlight from reaching the planet’s surface for months. Smit was a sedimentologist, and another researcher whom DePalma shared his data with, Mark Richards, now of the University of Washington, was a geophysicist. “Cretaceous mulch,” he said, dismissively; he already had many similar examples. During the winter months, when not in the field, DePalma prepared and analyzed his specimens, a few at a time, in a colleague’s lab at Florida Atlantic University, in Boca Raton. In July, 2012, the collector showed DePalma the site and told him that he was welcome to it.“I was immediately very disappointed,” DePalma told me. He holds the unpaid position of curator of vertebrate paleontology at the Palm Beach Museum of Natural History, a nascent and struggling museum with no exhibition space. For the first hundred million years of their existence, before the asteroid struck, mammals scurried about the feet of the dinosaurs, amounting to little.

Some scientists were wary. And yet the tektites fell into an active flood. After the fires died down, Earth plunged into a period of cold, perhaps even a deep freeze.

When the chips accumulated, he gathered them into small piles with a paintbrush; when those piles accumulated, Pascucci swept them into larger piles with a broom and then shovelled them into a heap at the far end of the dig.Occasionally, DePalma came across small plant fossils—flower petals, leaves, seeds, pine needles, and bits of bark.