It’s being dubbed the “Frankenstein” doctor, but scientists think it could be the missing link between plant-eating dinosaurs like the Stegosaurus, and the carnivorous dinosaurs like Tyrannosaurus rex. It’s called the Chilesaurus, a vegetarian dinosaur that roamed the Earth about 150 million years ago.

Scientists were initially confused by this dinosaur because it had weird phsyical characteristics that appeared to come from two separate groups of dinosaurs. It was originally found in South America, and had the head of a carnivore but flat teeth that were common for vegetarian dinosaurs who used them to grind up plants.

Scientists at Cambridge and London’s Natural History Museum examined more than 450 characteristics of early dinosaurs to figure out where Chilesaurus fit in in the dinosaur family tree. This latest study, published in the Royal Society’s Biology Letters, indicates that the animal belongs to Ornithischia, which is a “bird-hipped” group that includes Stegosaurus and Triceratops.