Near the highest lizard
Late Cretaceous – 75 - 67 Mya
North America: Montana, Alberta
Length: 9.1 meters (30 feet)
Height: 3.7 meters (12 feet)
Weight: 4,000 kg (8,818 lb)
Easily distinguished from other lambeosaurines, or duck-billed dinosaurs, by the tall neural spines which projected a tall back in profile, Hypacrosaurus also had a head crest that was distinct from other hadrosaurs. The crest likely functioned as both a tool for vocalization and for species recognition in mating as Hypacrosaurus shared the same ecological environment as Saurolophus and Edmontosaurus.
The growth rate of Hypacrosaurus was faster than that of tyrannosaurids such as Albertosaurus or Tyrannosaurus rex. Early reproductive maturity beginning by the age of 2 or 3 years ensured species replacement long before the animal reached its full growth by the age of 10 or 12.