Image Gallery: Boneheaded Dinosaurs Butt Heads

pachycephalosaur illustration
Pachycephalosaurs lived during the late Cretaceous Period, and often sported enormous domes on their heads encircled by spikes. (Image credit: ??)

Butting heads

pachycephalosaurs fighting

(Image credit: Ryan Steiskal)

A 2013 study by University of Wisconsin OshKosh researchers revealed that domeheaded dinosaurs may have butted heads in combat

Bonehead dinosaurs

pachycephalosaur dinosaur illustration

(Image credit: Ryan Steiskal)

Pachycephalosaurs were plant eating dinosaurs that roamed during the Late Cretaceous Period. They grew large domes on their head made of bone, and the domes were often encircled by spikes.

Bighorn battles

(Image credit: U.S. Fish & Wildlife Service)

Lots of animals scuffle over turf or mates. Bighorn sheep lock horns over territory and ewes.

Crocodile fight

Two Crocodiles

(Image credit: Patrick Foto | Shutterstock)

Crocodiles are known to bite viciously at each other in squabbles.

T. rex bites

(Image credit: Erica Lyn Schmidt.)

Even dinosaurs show evidence of fighting amongst themselves. Bite marks on juvenile T. rex fossils indicate that they may have bitten each other.

Common injuries

skull injuries in pachycephalosaurs

(Image credit: Joseph Peterson et. al)

To understand pachycephalosaur behavior better, Joseph Peterson, a geology professor at the University of Wisconsin Oshkosh and his colleagues analyzed skulls from the dome-headed dinosaurs.

Frequent injuries

ct scan of the domehead injuries

(Image credit: Joseph Peterson et al)

The team analyzed more than 100 skulls from museums around the world, using in-person analysis, high-resolution photographs, and CT scanning.

Extensive injuries

pachycephalosaur skull damage

(Image credit: Joseph Peterson et al.)

The team found that roughly 20 percent of the dinos had injuries, such as pit marks, on their skulls.

Similar profile

skull injuries in bighorn sheep

(Image credit: Joseph Peterson et al.)

The pit marks bore a close resemblance to injuries found on bighorn sheep skeletons. In sheep, the pitting is caused when they butt heads in combat.

Fighting dinosaurs

pachycephalosaurs fighting

(Image credit: Ryan Steiskal)

The boneheaded dinosaurs likely sustained their injuries when bashing their heads against rivals.

Skin infection

pachycephalosaurs fighting

(Image credit: Ryan Steiskal)

Those impacts may have broken the skin, causing infections.

Tia Ghose
Managing Editor

Tia is the managing editor and was previously a senior writer for Live Science. Her work has appeared in Scientific American, and other outlets. She holds a master's degree in bioengineering from the University of Washington, a graduate certificate in science writing from UC Santa Cruz and a bachelor's degree in mechanical engineering from the University of Texas at Austin. Tia was part of a team at the Milwaukee Journal Sentinel that published the Empty Cradles series on preterm births, which won multiple awards, including the 2012 Casey Medal for Meritorious Journalism.