A decade-old chance discovery of bone fragments on the property of Bill Shipp near Winifred, Mont., led to the recent identification of a new species of horned dinosaur - also referred to as ceratopsids. The new species, Spiclypeus shipporum, marks the ninth discovery of a new dinosaur species in the Judith River Formation in Montana.
The remains were preserved in a silty slope that was once a part of an ancient floodplain and include a skull, backbone, hips and part of the legs, all from a single dinosaur.
Ceratopsids were megaherbivores that evolved during the Late Cretaceous period, making their way into North American and Asia shortly afterward. At the time, they were one of the most expansive dinosaur groups and were easily recognizable due to their horned skulls and ornamental frills.
The Spiclypeus shipporum stands out among ceratopsids due to the bones above their eyes, which were oriented sideways out from the skull. In addition, they possessed unique bony spikes on the edge of their frill that varied in their orientation, with some projecting outwards and others curled.
"This is a spectacular new addition to the family of horned dinosaurs that roamed western North America between 85 and 66 million years ago," said Jordan Mallon of the Canadian Museum of Nature and lead author of the study. "It provides new evidence of dinosaur diversity during the Late Cretaceous period from an area that is likely to yield even more discoveries."
Following the discovery of the initial bone fragments, a team from the museum spent an additional two years excavating and recovering the remaining fossils from the dinosaur. Examination of the bones revealed signs of bone infection and arthritis.
"If you look near the elbow, you can see great openings that developed to drain an infection," Mallon said. "We don't know how the bone became infected, but we can be sure that it caused the animal great pain for years and probably made its left forelimb useless for walking."
Despite these problems, further analysis revealed that the mature dinosaur was around 10 years old at the time of its death.
The findings were published May 18 in the journal PLOS One.
