The palaeontologists believe they have found one of the biggest sites of dinosaur remains from a massive excavation pit. The fossilized bones date to the Upper Cretaceous just before to the Cretaceous–Paleogene extinction event. The findings also include the remains of a 20 meter (66 ft) hadrosaurid, a record size for the duck-billed dinosaur. A fossilized skull of a large ceratopsian was also found along with bones which belong to club-tailed ankylosaurs.