Sunday, 14 June 2015

Peter Hew's Regal Horned Face

The ceratopsians are the group of dinosaurs which include the well known species Triceratops. Like Triceratops, most group members possessed some kind of elaborate head ornamentation: head frills for mating displays and to baffle predators, horns for more pugilistic purposes. They are considered the most advanced groups of dinosaurs. Now a new member has been added to the ceratopsian family. The specimen was actually collected a decade ago by Calgary geologist, Peter Hews, who discovered the bones protruding from 70 million year old rocks exposed in the banks of the Oldman River in south-east Alberta, Canada.

The skull of the 70 million year old chasmosaurine
ceratopsian Regaliceratops peterhewsi
Alberta has yielded a multitude of dinosaur species over the decades, its rocks preserving the Cretaceous ecosystems in a wealth of detail. Nicknamed Hellboy, this new species is certainly one of the more flamboyant.

'From the onset we knew it was important,' said Caleb Brown from the Royal Tyrell Museum of Palaeontology, Alberta. 'However, it was not until the specimen was being slowly prepared from the rocks in the laboratory that the full anatomy was uncovered, and the bizarre suite of characters revealed.'

A set of pentagonal plates adorned the head frill, two small horns jutted out from above the eyes and a single large horn from the nose. The overall effect was rather crown-like and correspondingly the species was named Regaliceratops peterhewsi. The unique head ornamentation allowed its evolutionary relationships to be strongly identified. A close relative of Triceratops, Regaliceratops was part of a ceratopsian group known as the chasmosaurines. Its ornamentation, however, was closer to that found in centrosaurine ceratopsians. At 70 million years old it lived after the extinction of the centrosaurines, but the similarities in ornamentation point to an intriguing possibility: evolutionary convergence in dinosaurs.

An artist's impression of Regaliceratops peterhewsi
'Because this new species is one of the latest surviving horned dinosaurs, living at a similar time as Triceratops, it is also telling us that horned dinosaurs remained quite diverse right until the end,' said Steve Brusatte from Edinburgh University. 'To me, this is a strong hint that these dinosaurs were at or near the top of their game when that asteroid fell out of the sky.'

That said, almost as soon as it evolved, Regaliceratops's rule came to an abrupt end due to that same asteroid. No amount of ornamentation could prevent the ceratopsians to withstand a world in ecological flux.