The image of the triceratops is often conjured when one thinks of a horned dinosaur but the Ceratopsian group also includes a range of animals whose appearance looks different from that of the three-horned triceratops.
In a new study, paleontologists describe a new plant-eating species of dinosaurs called Hualianceratops wucaiwanensis. The prehistoric creature, which is characterized by a unique ornamental structure on its skull, is smaller than its more popular Triceratops cousin.
The anatomy of the discovered specimen suggests that the creature was an early horned dinosaur but it did not have any horn. Researchers though have already identified other horned dinosaurs that did not sport horns such as the Yinlong downsi, the oldest known member of the horned dinosaur family.
Hualianceratops is similar in age to Yinlong downsi although the former is slightly shorter and chunkier. Both ceratops species were likewise discovered in the same fossil bed in China's Xinjiang Province.
The new dinosaur, which was described in a study published in the journal PLOS ONE on Dec. 9, stood on its hind legs and was not much bigger than a cocker spaniel. Study researcher Fenglu Han, from the China University of Geosciences, and colleagues were able to reconstruct the body type of the dinosaur based on the skull and foot fossils that were unearthed in China.
The discovery of the species provides evidence that the Late Jurassic horned dinosaurs were much more diverse than earlier believed.
Study author Catherine Forster, from the George Washington's Geological Sciences Program, said that finding the two species in the same fossil bed shows that the group had more diversity than previously thought.
The findings provided evidence that the ceratopsian dinosaurs have already diversified into five lineages at the start of the Jurassic Period.
"Prior to 2006 no ceratopsians were known from the beginning of the Late Jurassic. In any case, this phylogeny implies that ceratopsian phylogenetic diversification was well established by the beginning of the Late Jurassic," the researchers wrote in their study.
The fossils also suggest that several lineages lived side by side about 160 million years ago during the early part of the Jurassic period.
"Identifying Hualianceratops allows us to expand the beaked family of dinosaurs, Ceratopsia, which includes popular species like Triceratops and Psittacosaurus," said Han. "Now we know the horned dinosaurs thrived in the early Late Jurassic, and they co-existed with Guanlong, which was an early relative of T. rex and maybe threatened them."