These particles were found at the Tanis fossil site in the US state of North Dakota.
Although 3,000 kilometers (1,865 mi) away from the crater, the site has preserved several remarkable discoveries, believed to be from the direct aftermath of the asteroid impact, in the sediment layers of an ancient lake.
The researchers said the dust particles were about 0.8 to 8.0 micrometres long – just the right size to persist in the atmosphere for up to 15 years.
By entering this data into climate models similar to those used for present-day Earth, the researchers determined that dust played a much larger role in the mass extinction than previously thought.
Of all the material released into the atmosphere by the asteroid, they estimated that it was 75 percent dust, 24 percent sulfur and one percent soot.
