Dinosaurs evolved frills, horns to attract mates: study

The elaborate frills and horns of a group of dinosaurs may have evolved to attract mates, and not to help species to recognise each other, a study has found.

It has been suggested that different species that live in the same location may evolve features in order to distinguish one another to help avoid problems such as hybridisation, where two individuals of different species produce infertile or unfit offspring, researchers said.

The researchers at Queen Mary University of London examined patterns of diversity in the ornamentation of 46 species of ceratopsians, the horned dinosaurs.

They found no difference between species that lived together and those that lived separately.

Previous research found that the frill in one ceratopsian species, Protoceratops, may have evolved under sexual selection.

The new findings published in the journal Proceedings of the Royal Society B, appear to add evidence to this across the entire group.

The researchers also found evidence that ornamental traits seemed to evolve at a much faster rate than other traits.

As these structures are costly to grow and maintain, this finding similarly points to a strong selective pressure on these traits.

"This resolves a long-standing and hitherto untested hypothesis concerning the origin and function of ornamental traits in ceratopsian dinosaurs," said Andrew Knapp, lead author of the study.

"We have shown that species recognition, one of the commonest explanations, is unlikely to be responsible for the diversity or origin of ornamentation in this group," said Knapp.

The researchers believe the implications extend beyond the scope of ceratopsians and have consequences for the study of evolutionary theory over vast stretches of time.