Drowning centrosaurus dinosaurs, illustration. These dinosaurs lived 76-74 million years ago, during the Late Cretaceous, in what is now Alberta, Canada. Researchers found two bonebeds containing many centrosaurus fossils of differing ages in the Albertan badlands. These mass graveyards could exist due to herds of migrating centrosaurus drowning in flash floods. They weighed up to 1,000 kilograms and reached 6 metres in length. Their skulls had several large horns, including a large bony frill covering the neck.