Have We Found the Last Dinosaur? Fossil Uncovered in Montana Adds Weight to Asteroid Extinction Theory

The prehistoric remains of a horned beast unearthed by fossil hunters in Montana is believed to belong to the last known dinosaur to walk the Earth. This colossal discovery adds weight to the theory that dinosaurs were wiped out by the impact of an asteroid.

The lone dinosaur horn is the last remaining part of the youngest dinosaur preserved before the catastrophic end to the Age of Dinosaurs 65.5 million years ago, researchers said on Wednesday. Other dinosaur fossils are either much older, or were uncovered after being washed from their original graves into much younger sediments well after they died.

Researchers spotted the 1.5 foot (45cm) long horn while searching for fossils in the Hell Creek Formation, a thick slab of mudstone in southeastern Montana, a region known for preserving fossils both before and after the mass extinction. On spotting the dinosaur horn, the researchers dug a trench next to the fossil and removed rock samples from numerous depths. These were then sent to Antoine Bercovici at the China University of Geosciences, who analyzed pollen grains in the rocks to identify the K-T boundary. When the asteroid hit, the existing plant life died out, and was later replaced with a growth of ferns.

Scientists say that the horn most likely belonged to an adult triceratops, a dinosaur that could grow to around 30 feet (9 meters) long and weigh up to 12 tons.

To be clear, the triceratops was unlikely to be the last dinosaur standing, merely the last survivor to be identified by paleontologists.

This is the youngest dinosaur that has been discovered in situ. Others can be found in younger deposits, but those have been put there by geological processes and are actually much older, said Tyler Lyson, a paleontologist at Yale University.

Read more at about the find first published Wednesday on Biology Letters.

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