Claim: The Hypacrosaurus is estimated to have been around 15 feet long, and weighed up to 4.4 tons with neural spines that projected from the top of the vertebrae, the bones that form the spinal column.
Evidence: The animal is estimated to have been around 9.1 meters (30 feet) long, and to have weighed up to 4.0 tonnes (4.4 tons).