We're almost certain that a giant meteor hit Earth 65 million years ago. But a mysterious "three-meter gap" in the fossil record might mean dinosaurs were already dying off. Now a newly discovered fossil might finally reveal the whole story.

Until now, paleontologists were unable to find any dinosaur fossils in the three meters below the KT boundary, which is the point where the meteor hit Earth. This strange gap has been interpreted as evidence that dinosaurs were already on the way out long before the meteor hit, and that their extinction might have been a gradual process due to more terrestrial forces rather than a sudden wave of destruction from space.

But now Yale researchers have discovered a triceratops horn just five inches from the KT boundary, which means it likely lived only a few tens of thousands of year before the impact, perhaps even just a few thousand. And it isn't merely a question of finding the fossil close to the boundary - the researchers have used more advanced techniques to make absolutely sure that the horn wasn't moved from an initial position that would have placed it earlier in time.


Of course, a single horn isn't enough to erase the three-meter gap. But the paleontologists are confident that using the same advanced techniques they utilized to confirm the horn's age will also reveal that many fossils discovered near the KT boundary actually died out far closer to the time of impact than originally realized. With some more careful testing, the researchers say, the three-meter gap may disappear entirely.

Via Yale University.