"Palaeontologists have long suspected that many of the strange features we see in dinosaurs were linked to sexual display and social dominance, but this is very hard to show," lead author David Hone noted in a release. "The growth pattern we see in Protoceratops matches that seen for signalling structures in numerous different living species and forms a coherent pattern from very young animals right through to large adults."

But why these dinosaurs had such outlandish and bizarre structures is by no means a settled question, and some have pushed back on linking it to sexual selection.

Much of the debate once centred on the usefulness of frills, horns and other structures for combat. More recently, some scientists have argued these structures were primarily useful in recognising others belonging to the same species.

Paleontologist Andrew Farke at the Raymond M. Alf Museum of Paleontology in California said this new study could point to the frills playing some role in reproduction. But, he added: "It's also likely that it could just be for how old are you relative to the next animal, so who gets to the food first?"

Many animals today have odd features that primarily serve as ways to attract mates. Co-author Rob Knell said in the release that "sexual selection is a massively important force in shaping biodiversity both now and in the past".