Tiny Dinosaur Fossil from Spain Rewrites Ornithopod Evolution
A newly discovered dinosaur fossil unearthed in Spain is challenging long-held beliefs about the evolution of ornithopods, a group of plant-eating dinosaurs that includes the iconic Iguanodon. The findings, published Sunday in the journal Papers in Paleontology, suggest that evolution experimented just as radically at small body sizes as it did with larger dinosaurs.
The fossils, discovered by Fidel Torcida Fernandez-Baldor from the Dinosaur Museum of Salas de los Infantes in northern Spain, represent at least five individual dinosaurs. The museum specializes in fossils from the Cretaceous period. “From the beginning, we knew these bones were exceptional because of their minute size,” Fernandez-Baldor stated in a press release from the Vrije Universiteit in Brussels, which collaborated on the study. “It is equally impressive how the study of this animal overturns global ideas on ornithopod dinosaur evolution.”
Ornithopods, meaning “bird foot,” are one of seven major groups of dinosaurs, characterized by their bipedal stance. The Iguanodon, reaching up to nine meters (30 feet) in length, is a well-known example of this group. However, the newly identified species, named Foskeia pelendonum, was significantly smaller, measuring just over half a meter – less than 20 inches – in length. The name Foskeia, derived from Greek, translates roughly to “light foraging,” according to Vrije Universiteit.
“This is not a ‘mini Iguanodon’, it is something fundamentally different,” explained Penelope Cruzado-Caballero from Universidad de La Laguna in Spain. “Its anatomy is weird in precisely the kind of way that rewrites evolutionary trees.”
Paleontologists are particularly intrigued by the complexity of Foskeia’s tiny skull. According to Marcos Becerra from Universidad Nacional de Cordoba, “miniaturization did not imply evolutionary simplicity — this skull is weird and hyper-derived.”
The discovery is helping to fill a significant gap in the fossil record. Thierry Tortosa of the Sainte Victoire Natural Reserve noted that the dinosaur “helps fill a 70-million-year gap, a small key that unlocks a vast missing chapter.”
Paul-Emile Dieudonne, from Argentina’s National University of Rio Negro, who led the research, emphasized the significance of Foskeia’s diminutive size. “Yet it preserves a highly derived cranium with unexpected anatomical innovations,” he wrote. “These fossils prove that evolution experimented just as radically at small body sizes as at large ones. The future of dinosaur research will depend on paying attention to the humble, the fragmentary, the small.”
