Scientists at a site in North Dakota believe they’ve found pieces of an asteroid that hit Earth about 66 million years ago off the Yucatan Peninsula that led to the slow extinction of dinosaurs.

When the asteroid struck, it sent molten debris into the air that later cooled into “spherules of glass,” which millions of years later were discovered on the North Dakota site known as Tanis preserved in amber, according to the New York Times.

Fragment tests show they not only contained unmelted rock but portions of limestone crust from the asteroid crater thousands of miles away.

There were also high amounts of iron, nickel, and chromium which are found in asteroid material.

“Every single speck that takes away from this beautiful clear glass is a piece of debris,” said Robert DePalma, an adjunct professor and University of Manchester graduate, during a speech at the NASA Goddard Space Flight Center this week, according to the Times.

“To see a piece of the culprit is just a goose-bumpy experience.”

DePalma’s findings have not undergone a peer-review yet but his supervisor, Professor Phil Manning told BBC he also believes the pieces are from the dinosaur-ending asteroid according to people.com.

“We were able to pull apart the chemistry and identify the composition of that material,” Manning said.

“All the evidence, all of the chemical data from that study suggests strongly that we’re looking at a piece of the impactor; of the asteroid that ended it for the dinosaurs.”