Brachylophosaur Top Vertebrae Process
Age: 80/75 Million Years Old
Cretaceous Era
Specimen: Top process with side processes to vertebrae
Discovered: Montana, Judith River Formation
Fossil measures 3' wide (from longest points)
 
Brachylophosaurus was a mid-sized member of the hadrosaurid family of dinosaurs. It is known from several skeletons and bonebed material from the Judith River Formation of Montana, the Wahweap Formation of Utah and the Oldman Formation of Alberta, living about 81-76.7 million years ago.
 
Brachylophosaurus is notable for its bony crest, which forms a horizontally flat, paddle-like plate over the top of the rear skull. Some, depending on their age, had crests that covered nearly the entire skull roof, while others had shorter, narrower crests. Some researchers suggest it was used for pushing contests, but it may not have been strong enough for this. Other notable features are a relatively small head, the unusually long lower arms and the beak of the upper jaw being wider than other hadrosaurs of that time.
 
Apart from the above, Brachylophosaurus was a typical hadrosaur which reached an adult length of at least 9 metres (30 ft). In 2010, Gregory S. Paul estimated maximum length at 11 metres (36 ft) resulting in weight of 7 metric tons (7.7 short tons). Like other hadrosaurs, Brachylophosaurus had features like cheeks to keep fodder in the mouth and dental batteries with hundreds of stacked teeth. These teeth could be used to chew efficiently, a feature rare among reptiles, but common among some cerapodan ornithischian dinosaurs like Brachylophosaurus.