A new species of centrosaurine - a member of the large horned dinosaurs called ceratopsians - has been discovered in southern Utah during paleontological and geological surveys in Grand Staircase-Escalante National Monument. The findings mark one of the few times that fossils of this group have been discovered in the southern portion of North America.
The new species is called Machairoceratops cronusi and was discovered by researchers from the Ohio University and the Natural History Museum of Utah (NHMU). Through comparisons with other horned dinosaurs, the team has revealed that it possessed many unique features that set it apart from other similar species.
"The discovery of Machairoceratops not only increases the known diversity of ceratopsians from southern Laramidia, it also narrows an evolutionary information gap that spans nearly 4 million years between Diabloceratops eatoni from the lower middle Wahweap Formation and Nasutoceratops titusi from the overlying Kaiparowits Formation," said Eric Lund of Ohio University and lead author of the study.
The unique horned beast lived approximately 77 million years ago during the end of the Cretaceous Period. The Centrosaurine ceratopsids dinosaurs - including the Machairoceratops - were known for their herbivorous nature, facial horns and neck shields. Although the new species possesses these characteristics, it also stands apart for several reasons.
"Machairoceratops is unique in possessing two large, forward curving spikes off of the back of the neck shield, each of which is marked by a peculiar groove extending from the base of the spike to the tip, the function of which is currently unknown," Lund said.
The fossils also reveal insights into the early evolutionary history of ceratopsids on Laramidia, suggesting that they made their home on two different regions within the continent, each of which likely posed different evolutionary pressures on the creatures within them.
"An effort like this underscores both the necessity and excitement of basic, exploratory science in order to better understand the history of the world around us," said Patrick O'Connor of Ohio University and co-author of the study. "Even in a place like western North America, where intense work has been conducted over the past 150 years, we are still finding species new to science."
The findings were published in the May 18 issue of the journal PLOS One.