CLEVELAND, March 12, 2012 /PRNewswire-USNewswire/ -- Two new horned dinosaurs have been named based on fossils collected from Alberta, Canada. Unescoceratops koppelhusae and Gryphoceratops morrisoni are new species from the Leptoceratopsidae horned dinosaur family. The herbivores lived during the Late Cretaceous, between 75 to 83 million years ago. The specimens are described in Cretaceous Research.

"These dinosaurs fill important gaps in the evolutionary history of small-bodied horned dinosaurs that lack the large horns and frills of relatives like Triceratops from North America," said lead author Michael Ryan, Ph.D., curator of vertebrate paleontology at The Cleveland Museum of Natural History. "Although horned dinosaurs originated in Asia, our analysis suggests that leptoceratopsids radiated to North America and diversified here, since the new species, Gryphoceratops, is the earliest record of the group on this continent."

Unescoceratops koppelhusae lived approximately 75 million years ago. Measuring about one to two meters (6.5 feet) and weighing less than 91 kilograms (200 pounds), it had a short frill behind its head, no skull ornamentation and a parrot-like beak. Its teeth were lower and rounder than those of any other leptoceratopsid. Its hatchet-shaped jaw had a bone that projected below the jaw like a small chin.

The lower left jaw fragment of Unescoceratops was discovered in 1995 in Dinosaur Provincial Park, a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site by Philip Currie, Ph.D., now of the University of Alberta. Described in 1998 by Ryan and Currie, the dinosaur was referred to as Leptoceratops. Subsequent research by Ryan and the Royal Ontario Museum's David Evans, Ph.D., determined the specimen was a new genus and species. The genus is named to honor the UNESCO site designation for the locality where the specimen was found and from the Greek "ceratops," meaning "horned face." The species is named for palynologist Eva Koppelhus, Ph.D., wife of Currie.

Gryphoceratops morrisoni lived about 83 million years ago. It had a shorter and deeper jaw than other leptoceratopsids. Researchers believe it was a full-grown adult. Based on unique characters of the jaw and its size, researchers believe it was an adult less than one-half meter in length. This makes it the smallest adult horned dinosaur in North America and one of the smallest adult plant-eating dinosaurs known.

Lower right jaw fragments of Gryphoceratops were discovered in southern Alberta in 1950 by Levi Sternberg while working for the Royal Ontario Museum. The genus is named for "Gryphon," a mythological Greek figure with the body of a lion and the head of an eagle—a reference to the animal's beaked face. The species name honors Royal Ontario Museum technician Ian Morrison.

Second author Evans, of the Royal Ontario Museum, said, "Small-bodied dinosaurs are typically poorly represented in the fossil record, which is why fragmentary remains like these new leptoceratopsids can make a big contribution to our understanding of dinosaur ecology and evolution."

Contributing authors are Philip Currie, Ph.D., University of Alberta; Caleb Brown, University of Toronto; and Don Brinkman, Ph.D., Royal Tyrrell Museum of Palaeontology.

Images at www.cmnh.org.

SOURCE Cleveland Museum of Natural History