Scientists have solved the puzzle of the so-called "Frankenstein dinosaur", which seems to consist of body parts from unrelated species.
A new study suggests that it is in fact the missing link between plant-eating dinosaurs, such as Stegosaurus, and carnivorous dinosaurs, like T. rex.
The finding provides fresh insight on the evolution of the group of dinos known as the ornithischians.
Matthew Baron, a PhD student at Cambridge University, told BBC News that his assessment indicated that the Frankenstein dinosaur was one of the very first ornithischians, a group that included familiar beasts such as the horned Triceratops, and Stegosaurus which sported an array of bony plates along its back.
"We had absolutely no idea how the ornithischian body plan started to develop because they look so different to all the other dinosaurs. They have so many unusual features," the Cambridge scientist said.
"In the 130 years since the ornithischian group was first recognised, we have never had any concept of how the first ones could have looked until now."