Pachycephalosaurus's skull was up to 10 inches thick, but scientists still debate exactly how it was used – whether for head-butting, or perhaps more for flank-butting or display. elaborate
Tarbosaurus bataar, despite its name and appearance, wasn't actually a Tyrannosaurus. It was a close relative, but belonged to a different genus. elaborate
Acrocanthosaurus had spines along its back that were much taller than those of most other theropods, possibly supporting a hump or sail. elaborate
The crest of a Parasaurolophus may have been used to amplify its calls, creating a sound that could travel long distances. elaborate
Styracosaurus had a large bony frill and up to six long horns on its face, but its horns were not directly attached to the frill itself. elaborate