Torosaurus Dinosaur Bone, from Hell Creek Formation, Northern Montana, U.S.A. (No.16)

Torosaurus was a species of ceratopsid dinosaur that lived during the Late Cretaceous period. The most well known type of ceratopsid is the three horned Triceratiops. It’s was thought that actually Triceratops was the juvenile of Torosaurus and they were the same species with Torosaurus being the Triceratops in full maturity but this is still debated, with a recent study in 2012 concluding that Torosaurus and Triceratops were two different species of Ceratopsidae. 

Torosaurus had a much more elongated skull compared to a Triceratops, which could be up to 2.77 meters (9.1 ft) in length, one of the largest skulls of any known land animal. The skull had large openings in the frill and five or more pairs of hornlets on the back of the frill. Torosaurus also lacked the long nose horn. 

From head to tail Torosaurus could grow up to 8 to 9 meters (26 to 30 ft) long and weigh 4 to six tones.