Morelladon: Spain’s High-Spined Herbivore
Sail backs were all the rage back in the Mesozoic. Some spinosaurs had them, with Spinosaurus itself bearing one of the most ornate of all, as well as the herbivorous Ouranosaurus, the shark-finned Concavenator, and the strange Deinocheirus, among others. And now, thanks to paleontologist José Miguel Gasulla and colleagues, another high-spined dinosaur has joined the club.
The Early Cretaceous herbivore, named Morelladon beltrani, didn’t have the most ornate ornament of the various sailbacks. The tall spines would have given it more of a high, narrow bump, superficially similar to the midline ridge of the carnivorous Acrocanthosaurus that was terrorizing North America around the same time.
What has continued to puzzle paleontologists, however, is why so many lineages of dinosaurs repeatedly evolved tall backs. No one knows for sure. The answer isn’t environmental, as high-spined dinosaurs lived in disparate habitats, and hot-running dinosaurs did not require sails to heat up, as early hypotheses supposed. The frontrunner right now is that they evolved for decoration, either to impress potential mates, intimidate rivals, or help members of the same species identify each other at a distance.
The latter possibility might be a good fit for Morelladon. During the Early Cretaceous, Gasulla and colleagues write, the Iberian Peninsula was home to a diverse group of dinosaurs that were variations on the theme of Iguanodon. They were so similar to each other that paleontologists have only just started to recognize how many different species and genera there were within a collection of bones that used to bear the Iguanodon title, and so it may be that the high spines of Morelladonhelped the dinosaur stick with its own kind and avoid embarrassing encounters like approaching the wrong species come mating season.
Name: Morelladon beltrani
Meaning: Morelladon means “Morella tooth” in reference to the place the dinosaur was found, and beltrani honors Victor Beltrán “for his involvement and collaboration in the localization of the different fossil sites at the Mas de la Parreta Quarry.”
Age: Around 125 million years old.
Where in the world?: Castellón, eastern Spain.
What sort of critter?: An ornithopod dinosaur related to Iguanodon.
Size: About 20 feet long, similar to its relative Mantellisaurus.
How much of the creature’s body is known?: A tooth, six nearly-complete vertebrae and additional fragments of spine, the sacrum, most of the hips, a tibia, rib fragments, and two chevrons.
Gasulla, J., Escaso, F., Narváez, I., Ortega, F., Sanz, J. 2015. A new sail-backed styracosternan (Dinosauria: Ornithopoda) from the Early Cretaceous of Morella, Spain. PLOS ONE. doi:10.1371/journal.pone.0144167