The dinosaur fossil found in 2005 in Winifred, Montana turns out to be a new species of a horned dinosaur. The remains were from a 10-year-old Spiclypeus shipporum, a four-legged herbivorous dinosaur that had head frill and triangular spikes, which lived about 76 million years ago.

The study, published online on May 18 in the journal PLOS ONE, states that Spiclypeus shipporum, nicknamed Judith, is an addition to an increasing collection of newly discovered four-legged dinosaurs distinguished by their head frills and horns, also known as ceratopsids. The name spiclypeus means spiked shield in Latin while hipporum is after the Shipp family, the owner of the land where the dinosaur was unearthed.

However, unlike the famous Triceratops, Judith’s horns extend sideways from the skull. Judith’s spikes at the back of its frill project outward unlike another ceratopsian dinosaur called Kosmoceratops, whose frills curl forward.

Spiclypeus shipporum

Jordan Mallon and the reconstructed skull of Spiclypeus shipporum. Credit: Canadian Museum of Nature

“This is a spectacular new addition to the family of horned dinosaurs that roamed western North America between 85 and 66 million years ago,” says Jordan Mallon, a palaeontologist at the Canadian Museum of Nature. “It provides new evidence of dinosaur diversity during the Late Cretaceous period from an area that is likely to yield even more discoveries.”

Bone analysis reveals that this Spiclypeus suffered from arthritis and osteomyelitis, a bone infection. Openings on its elbow could have been the drainage for the infection, suggesting that the dinosaur struggled from great pain for many years and is unable to walk on its left forelimb.

The researchers assert that the Spiclypeus is unique to Montana. This indicates that dinosaurs that lived 76 million years ago in western North America were highly localised.

The Spiclypeus shipporum will be presented in a public exhibit this coming May 24 at the Canadian Museum of Nature in Ottawa. Viewers can see all the bones discovered, which includes the dinosaur’s skull and humerus.