According to researchers, head crests, horns and other large ornamented structures found in dinosaurs were likely utilized in sexual displays as well as to assert social dominance. Researchers from the Queen Mary University of London came to this conclusion after analyzing Protoceratops, publishing their findings in the journal Palaeontologia Electronica.

Closely resembling sheep in size, Proceratops are characterized by a large bony frill extending from the back of their heads over their necks. The researchers went over 37 specimens from fossils discovered in the Gobi desert's Djadochta Formation and from previously published research. They examined the dinosaur's bony frill for changes in width and length across four stages in the Protoceratops life: adults, near-adults, young animals and hatchling babies.

Based on their findings, the researchers saw that Protoceratops had disproportionately larger bony frills depending on their size, which grew bigger as they aged. At the same time, the frills didn't just change in size but in shape as well.

As the researchers observed that the bony frills were absent in young Protoceratops then suddenly became more prominent as the dinosaur matured, they suggested that the structure's function could be related to sexual selection and used for attracting suitable mates, much like how a male peacock uses its tail to gain the attention of a female.

According to David Hone, one of the authors for the study, paleontologists have long had suspicions that strange features in dinosaurs are used as a show of social dominance associated with sexual display except they didn't have hard evidence to prove it.

"The growth pattern we see in Protoceratops matches that ... and forms a coherent pattern from very young animals right through to large adults," he said.

Through this study and others, more and more biologists are realizing that sexual selection is a major force that shaped biodiversity in the past and can mold today's. In part, it also accounts for how new species arise, the effects on extinction rates, as well as the ways animals adapt to their changing environments.

Other authors for the study include Robert Knell and Dylan Wood.

Photo: Jordi Payà | Flickr