Scientists have found a massive crater in Antarctica and say it may have been caused by a meteor that helped pave the way for the rise of the dinosaurs.
An American geologist says the 300-mile wide crater is more than a mile beneath a sheet of ice.
It was discovered using satellite data.
He says the crater could date back 250 million years to a time when almost all animal life on Earth died out.
The extinction is also believed to have helped dinosaurs rise to prominence.
Researchers hope to find other evidence, such as rocks, that could help them firmly date the crater.