Ironically, the dinosaur-killing asteroid that plunged Earth into a prolonged ‘impact winter’ likely occurred in the late Spring to early Summer 66 million years ago.
This is the conclusion of a team led from the University of Manchester who studied deposits at the Tanis fossil site in North Dakota that formed at the time of the impact.
To narrow down the time of the impact, the team performed multiple different analyses of the annual growth lines in fossil fish bones