These dinosaurs may have used their frills to flirt
New research has found the neck frill of ceratopsians, a colourful bulge on top of their head and neck, likely came about to attract mates. Experts have long sought to determine why dinosaurs had decorative skull shapes. It had been unclear whether the frills, like the ones found on the triceratops, were for battle, intimidation or to attract mates.
Typically a sexual trait will be distinct, vary more and grow more quickly when compared with other bodily features, the study authors said, allowing it to evolve without affecting the development or function of other regions.
Dr Knapp and his colleagues 3D scanned 30 complete skulls of protoceratops, raging in size from newly born to fully grown adults.
This allowed the team to compare the development of the skulls, according to the research published in Proceedings B.
In creatures today which display sexual selection, certain features show a distinct pattern of growth, known as allometry.
When allometry is disproportionately bigger than the growth of other traits, it is “almost always a sexually selected feature, such as the antlers of a deer”, the Natural History Museum said.
The frills of protoceratops displayed growth patterns consistent with allometry, indicating that the frills were very possibly sexually selected.
Dr Knapp continued: “While there are quite a few examples in living animals where usually females select males based on the size of their tail feathers or calls, it is quite often overlooked that males do the same thing with females as well.
“In a species of bird known as the crested auklet, both males and females have an impressive plume of feathers curling from the tops of their heads used by each sex to signal their health.
“So while the plume of feathers is a sexually selected trait, it has not lead to sexual dimorphism.
“Sexual selection is a bit more complex than the bigger the male trait the more successful it is.
“There almost certainly were differences between males and females but quite often differences are in body size, so males will be bigger than females or vice versa. It could also have been through something else like colouration, which doesn’t preserve in fossils.”
