67 to 65 million years ago
Late Cretaceous period
Torosaurus was discovered by John B. Hatcher and named in 1891. Evidence for the Torosaurus includes several partial skulls and incomplete skeletons from Alberta to New Mexico. In all, 21 skeleton fragments have been identified as Torosaurus, but there is debate amongst paleontologists as to how many species of Torosaurus existed. The 2.6 metre skull of Torosaurus is the largest known from any land animal.
Torosaurus was a “bird-hipped” dinosaur from the group known as the horn-faced dinosaurs or ceratopians. It was a large sociable herbivore with a strong beak, able to handle the toughest vegetation including small branches. It had powerful legs that were short at the front and longer at the back, which gave it a very stable posture. Its skull had two brow horns, a short nose horn and a long-frilled crest giving it a fierce appearance.
Many theories have been proposed for the enormous crested skull of dinosaurs such as Torosaurus. It was originally thought that its crest was used primarily for defence or to house massive muscles for eating tough vegetation. The presence of two large holes in the crest led palaeontologists to believe that it was used for sexual display and to intimidate opponents. The holes would have been covered by stretched skin creating vivid eye-spots when flushed with blood.