A rare type of meteorite known as a carbonaceous chondrite was likely the object that slammed into Earth 66 million years ago and triggered the extinction of about 75 per cent of all species, including every non-avian dinosaur. 

Researchers concluded this by analysing nickel isotopes preserved in material left behind by the Cretaceous-Paleogene impact. The material came from a thin layer of clay deposited around the world after the impact.