Scientists have discovered a new species of dinosaur with a unique physical feature which made it stand out from the crowd.
The team of researchers found the fossil in what is now northeastern Spain, which would have been a lush river delta filled with ferns and conifers 125 million years ago. There were no other creatures of their kind in the Cretaceous Period, with the beasts distinguished by a strange sail-like structure on their backs.
Fossilized remains of new dinosaur species found in northeastern Spain
Scientists have no real idea what the function of the sail would have been, and research continues around the town of Morella. The fossilized remains of the medium-sized dinosaur were found in the Castellón Province of Spain, and the dinosaur has been named Morelladon.
“The generic name (of the new dino) is derived from Morella, the name of the type locality, and ‘odon,’ the Greek word for tooth,” wrote lead author José Miguel Gasulla from Grupo Biología Evolutiva (UNED-UAM).
The animal was a four-legged herbivore that measured around 20 feet in length, with a series of bony spines sticking out from its back to form a sail-like structure some 2 feet in height.
“The sail could help in heat exchange – thermoregulation – focused on releasing excess body heat into the environment, like the ears of the modern-day elephants, or as a storage place for fat to be used during periods of low food supply,” said paleontologist Fernando Escaso of the National University of Distance Education’s Evolutionary Biology Group in Spain.
Sail-backed animals have a long and varied history
Escaso later added that the structure could have been used to attract mates. Sail-like features have appeared periodically throughout the evolutionary history of vertebrates, and many of the animals which have had them are not closely related to each other.
A similar dinosaur known as Ouranosaurus lived around the same time in Africa. Another sail-backed creature called Spinosaurus was the largest dinosaur predator on record, measuring around 15 meters in length and weighing approximately 7 tons.
Other sail-backed creatures lived millions of years before the dinosaurs, including a carnivorous reptile called Arizonasaurus, the amphibian Platyhystrix and distant mammal relatives Dimetrodon and Edaphosaurus. Morelladon was identified from a partial skeleton which includes spines, vertebrae, pelvic bones, a thigh bone and teeth.
When Morelladon was alive, northeastern Spain would have experienced wet and dry periods, along with wide variations in temperature from 4 Celsius to 40 Celsius. According to Escaso, Morelladon would have been prey to Baryonyx, a relative of Spinosaurus, and would have lived alongside other plant-eating dinosaurs, crocodilians and flying reptiles called pterosaurs.
Morelladon shows many similarities with Iguanodon
The study authors think that Morelladon shared features with one of the most successful dinosaurs in history, Iguanodon. The large herbivore managed to colonize large swathes of the globe during the early-to-mid Cretaceous.
It was mostly two-legged, but did boast substantial forelimbs, and had a broad, stiff tail like that of the Morelladon. Scientists believe that its thumbs evolved into sharp spikes. Dinosaurs in the group are referred to as iguanodontoids, and the researchers believe that Morelladon is the latest member of the group.
“We knew the dinosaur fauna from Morella was similar to those of other contemporary European sites. However, this discovery shows an interesting rise of the iguanodontoid diversity in southern Europe around 125 million years ago,” said study co-author Fernando Escaso of the Universidad Nacional de Educación a Distancia.