A newly-found dinosaur fossil is the strongest evidence to date that dinosaurs were still roaming the earth when an asteroid hit Mexico 65 million years ago.
Scientists have long disagreed over what caused the mass extinction of the dinosaurs. One hypothesis is that the prehistoric animals were killed after the asteroid hit. Others believe that the dinosaurs were already extinct, or in decline at that time.
Critics of the asteroid impact hypothesis have pointed to the lack of dinosaur fossils right below the Cretaceous-Tertiary (K-T) boundary, the layer of the earth thought to be formed after the asteroid hit the planet. If the dinosaurs died during the massive impact, why hadn’t paleontologists found any fossils in the zone right below the K-T boundary?
Other researchers have contested the notion, suggesting this layer only appears devoid of fossils because fossils can get easily destroyed over millions of years. Also, the placement of the boundary can be uncertain, meaning that dinosaurs might have actually been found in this zone before but not reported.
Now scientists have discovered a fossil in this supposedly barren zone. Researchers from Yale University discovered a triceratops horn a mere five inches below the K-T boundary, in the Hell Creek formation in Montana.
Just because one dinosaur has been found in the gap doesn’t necessarily falsify the idea that dinosaurs were in decline. However it does indicate that at least some dinosaurs were doing fine right up to the K-T boundary.
