Chilesaurus: New Dinosaur Species Discovered In Chile
Meet the veggie T-Rex. Although closely related to iconic meat-eating dinosaurs, Chilesaurus was an herbivore
Chilesaurus, an entirely new dinosaur species, was apparently the Mr. Potato Head of the Late Jurassic. As described today in a study in the journal Nature, Chilesaurus had the teeth of an apatosaur, the arms of an allosaur and the axial skeleton of a ceratosaur. A member of the theropod clade, Chilesaurus was essentially an adorable, turkey-sized, vegetarian T-Rex.
“It’s a new species, genus and completely new lineage of dinosaurs that wasn’t known before,” says Martín Ezcurra, a doctoral researcher at the University of Birmingham and coauthor of the study. “Theropods were quite common during the Mesozoic, but in this part of Chile, this is the first plant-eating theropod dinosaur.”
Seven-year-old Diego Suarez initially stumbled across the Chilesaurus fossils in 2005, while hiking with his parents near the Andes mountains. The skeletons were remarkably complete, but paleontologists were less excited—they assumed that Suarez had discovered several different species of well-known theropods. It was only in 2008, when scientists looked more closely at the findings, that they realized the skeletons likely represented an entirely new, albeit enigmatic, species.
“The most interesting thing about this new dinosaur is that different parts of the body resemble different, unrelated groups,” Ezcurra says. “It show us how convergence evolution works.” (Convergence evolution is when organisms evolve certain traits independently, due to having to contend with similar conditions—not a common ancestry).
After the fossils were carefully removed from the surrounding rock—a process that took about five years—Ezcurra and his team began their analysis. They were surprised to find that all signs point to Chilesaurus belonging to Therapoda, a clade that includes velociraptors and tyrannosauruses, as well as modern bird species. From the paper:
“The bizarre anatomy of Chilesaurus raises interesting questions about its phylogenetic relationships. We scored Chilesaurus into four different integrative archosauriform, theropod and sauropodomorph data sets. Remarkably, all these analyses placed Chilesaurus as a member of Theropoda, near the origin of tetanurans.”
Ezcurra suspects that Chilesaurus’ novelty within dinosaur lineages will make it a prime subject for future study. “I think a lot of people will be very interested in studying this dinosaur,” he says. “It’s so different from other groups that its relationships in the genealogical tree of dinosaurs will prove very interesting.”