When seismic waves from the Chicxulub impact reached what is now North Dakota roughly ten minutes after the asteroid struck, they appear to have triggered a ten-metre standing wave in an inland river that flung fish onto the bank and buried them under glass beads still falling from the sky. (opens in new tab)

Robert DePalma was digging at a ranch in the Hell Creek Formation of southwestern North Dakota, in a place he eventually named Tanis. What he found there, layered into about a metre and a half of mudstone, reads less like a fossil bed and more like a crime scene photograph of the worst day in […]