A recently discovered dinosaur fossil might prove once and for all that dinosaurs went out with a bang.
The found fossil was a horn, thought to belong to a member of the dinosaur family that includes the Triceratops, found in a geological dig in southeast Montana. However, Wired reports that what’s really important about this particular bone is not the location where it was found, but the depth at which it was found: just five inches below the Cretaceous-Tertiary rock barrier, the spot on the fossil timeline where dinosaurs ceased to exist. That the fossil was found so close to this boundary suggests that dinosaurs went extinct very suddenly — as if, say, an asteroid hit the earth and wiped them out.
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If your first response is “no kidding, everyone knows that,” then you’ve probably taken third-grade science. You are also wrong. The theory has been debated for 30 years, according to research published in Biology, Letters. While the most widely-held theory of extinction is that dinosaurs were wiped out by a massive asteroid that hit Mexico’s Yucatan Peninsula at the end of the Cretaceous period, there have been dissenters. Critics of the asteroid theory often point to something known as the “3m gap”, write the researchers, which refers to the lack of dinosaur fossils found in the three meters of Upper Cretaceous rock; some argued that the gap indicated that dinosaurs gradually died out, instead of all at once.
Not so, according to the scientists who are arguing that the discovery of the “youngest known dinosaur bones”, wipes out any doubts over the asteroid theory, just as the asteroid wiped out the dinosaurs. (via Wired)
Megan Gibson is a reporter at TIME. Find her on Twitter at @MeganJGibson. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.