Europe's most complete stegosaurian skull unearthed in Teruel, Spain

Stegosaurs were dinosaurs mainly characterized by being plant-eaters, moving on all fours, and displaying two rows of plates and/or spines from the neck to the end of the tail. The specimen studied was recovered during the palaeontological excavations led by the Fundación Dinópolis at the "Están de Colón" fossil site, located in sediments of the Villar del Arzobispo Formation, dating to the Late Jurassic epoch (around 150 million years ago). It is the best-preserved stegosaurian skull ever found in Europe and has been identified as belonging to the species Dacentrurus armatus.

Sergio Sánchez Fenollosa, a researcher at the Fundación Dinópolis and co-author of the study, explains: "The detailed study of this exceptional fossil has allowed us to reveal previously unknown aspects of the anatomy of Dacentrurus armatus, the quintessential European stegosaur, which in 2025 marks 150 years since its first description. Dinosaurian skulls are rarely preserved due to the extreme fragility of their bones. This discovery is key to understanding how stegosaurian skulls evolved.

Furthermore, alongside the anatomical study, we have also proposed a new hypothesis that redefines the evolutionary relationships of stegosaurs worldwide. As a result of this work, we have formalized the definition of a new group called Neostegosauria."

According to the researchers, this new group includes medium to large-sized stegosaurian species that at least lived in what is now Africa and Europe during the Middle and Late Jurassic, in North America during the Late Jurassic, and in Asia during the Late Jurassic and Early Cretaceous.

Alberto Cobos, managing director of the Fundación Dinópolis and co-author of the publication, adds: "This dual achievement-both the study of an exceptional fossil and the proposal of a new evolutionary hypothesis-positions this research as a global reference in stegosaurian studies.

This fossil site from Riodeva continues to be a subject of research and still holds numerous relevant fossils, including more postcranial elements from the same adult specimen and, notably, juvenile individuals, a particularly rare combination in this type of dinosaurs. These discoveries continue to exponentially increase the palaeontological heritage of the province of Teruel, making it one of the iconic regions for understanding the evolution of life on Earth."