Volcanoes may have played a role not just the asteroid.
https://www.latimes.com/science/sciencenow/la-sci-sn-volcanoes-asteroid-extinction-20190221-story.html?fbclid=IwAR2EdMUgpg6r9vLC8f_BEgXu9I1xjFbYzGnnT4PEswA44vmxwGAzImANTUE
