According to foreign media reports, a type of horned dragon that lived in New Mexico 82 million years ago is considered to be one of the earliest known species of horned dragons. The researchers published their findings in PalZ (Paläontologische Zeitschrift). Horned dragons are characterized by horns and frills, in addition to a beak-shaped face. Now, Menefeeceratops sealeyi provides scientists with important information to understand the evolution of ceratosaurs.
In particular, the discovery reveals the centrosaurine subfamily of ceratosaurine, of which Menefeeceratops are thought to be the oldest members. Its remains give a clearer picture of the evolution of the group before its extinction at the end of the Cretaceous period.
Peter Dodson, who specializes in horned dragons, noted: "Over the past two decades, our understanding of the species of horned dragons has grown significantly. Most of these findings came from discoveries further north, from Utah to Alberta. What's particularly exciting is that this horned dragon found so far south is much older than any previously discovered horned dragon. It emphasizes the importance of the Menefee dinosaur fauna for understanding the evolution of the Late Cretaceous dinosaur fauna throughout western North America. ”
Fossil specimens of the new species — including multiple bones from one individual — were originally discovered in 1996 by Paul Sealey, a researcher at the Museum of Natural History and Science in New Mexico, in the Menefee Formation Cretaceous rocks of northwestern New Mexico. A field worker at the Museum of Natural History and Science in New Mexico collected the specimen. The following year, Tom Williamson of the Museum of Natural History and Science in New Mexico gave a brief description of this, and more recent studies of other ceratosaurs and further preparation of the specimen provided important new clues to the fossils.
Based on the latest survey, the researchers determined that the fossils represent a new species. The genus Menefeeceratops refers to the rock formations in which it was found, the Menefee Formation, and the taxa Ceratopsidae to which the species belongs. It is reported that the species is named Sealeyi in honor of Sealey, who excavated the specimen.
Menefeeceratops, although associated with another horned dinosaur, Triceratops, predates Triceratops. However, compared to Triceratops, Menefeeceratops was a relatively small group of dinosaurs, growing to 13 to 15 feet in length, while Triceratops could grow up to 30 feet long.
Horned dragons are usually large, rhino-like herbivores that may prefer to live in groups or in groups. They were important members of the Late Cretaceous ecosystem in North America. Researcher Steven Jasinski said: "In the late Cretaceous period, close to the end of the dinosaur era, in different parts of western North America, ceratopsa were more widely known. But we have less information about this group, and when you go back about 79 million years ago, their fossils are also rarer. ”
Although researchers have not yet found the bones of the entire dinosaur, a considerable part of the skeleton has been preserved — including part of the skull, jaw, forearm, hind limbs, pelvis, vertebrae and ribs. These bones not only suggest that the animal is unique among known dinosaur species, but also provide additional clues to its life history. For example, these fossils show evidence of a potential pathology that was caused by minor injuries or diseases on at least one vertebra near the base of the spine.
Some of the key features that distinguish Menefeeceratops from other horned dragons include the scaly bones that make up the dinosaur's frills. Although not as ornate as other horned dragons, the scaly membrane of Menefeeceratops has a distinctly concave and convex pattern.
By comparing the characteristics of Menefeeceratops and other known horned dragons, the team tracked their evolutionary relationships. Their analysis placed Menefeeceratops sealeyi at the bottom of the evolutionary tree of the centrosaurines subfamily, suggesting that Menefeeceratops is not only one of the oldest known centrosaurine horned dragons, but also one of the most fundamental evolutionary ones.
"Menefeeceratops are part of a thriving Cretaceous ecosystem in the southwestern United States, along with many of its more well-known members who predate dinosaurs near the end of the Cretaceous period," Jasinski noted. ”