May 31, 2016

By Rhesa Ledbetter

A new horned dinosaur species was unearthed in Grand Staircase-Escalante National Monument. The dinosaur lived around 77 million years ago during the Late Cretaceous period. The finding was recently published in the peer-reviewed journal, PLOS One. Eric Lund, lead author, said the dinosaur has some unique characteristics not seen in other horned species. In fact, the dinosaur’s name, Machairoceratops cronusi, is in reference to what many find to be its most distinguishing feature- bent ‘sword-like’ spikes.

“[The dinosaur] has two horns over the eyes. It’s related to triceratops, just occurred about 10 million years earlier. Horned dinosaurs had this big frill or neck shield that came off the back of the head. But unlike other horned dinosaurs, [Machairoceratops] has these two large hooks that project up and forward over the neck shield. That’s a unique morphology unto itself, but there is also a groove on the big spikes, which is a characteristic not ever seen before in horned dinosaurs,” said Lund.

As for the function of the unique spikes on the neck shield- one can only speculate. Lund said they were most likely a sexual display feature, but that other possibilities include use in recognition or competition.

Although, the research team recovered only cranial elements, they were able to infer what the dinosaur ate and estimate its relative size.

“We don’t have any of the preserved teeth, but we know all horned dinosaurs were plant-eaters. So, we can assume this dinosaur was the same,” Lund said. “We believe the dinosaur was 1-2 tons and 6-8 meters long. It’s not one of biggest of the horned dinosaurs, but still a big animal.”

This new finding provides a deeper understanding of our pre-historic past.

“This animal helps fill in an evolutionary information gap. Machairoceratops also retains some features that help us make inferences about evolutionary pressures acting upon the dinosaurs during this particular time period,” said Lund.

The dinosaur fossils are currently housed at the Natural History Museum of Utah. They are not displayed as part of a public exhibit, but can be viewed by contacting the collections manager.

Journal reference: Eric K. Lund, Patrick M. O’Connor, Mark A. Loewen, Zubair A. Jinnah. A New Centrosaurine Ceratopsid, Machairoceratops cronusi gen et sp. nov., from the Upper Sand Member of the Wahweap Formation (Middle Campanian), Southern Utah. PLOS ONE, 2016; 11 (5): e0154403 DOI: 10.1371/journal.pone.0154403