Cretaceous–Paleogene boundary - Wikipedia
https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_boundaryExtraterrestrial Cause for the Cretaceous-Tertiary Extinction | Science
http://science.sciencemag.org/content/208/4448/1095The Bizarre Bird That’s Breaking the Tree of Life | The New Yorker
https://www.newyorker.com/science/elements/the-bizarre-bird-thats-breaking-the-tree-of-lifeThe Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary | Science
http://science.sciencemag.org/content/327/5970/1214The Day the Dinosaurs Died | The New Yorker
https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died