A new specimen of Dacentrurus armatus Owen, 1875 (Ornithischia: Thyreophora) from the Upper Jurassic of Spain and its taxonomic relevance in the European stegosaurian diversity.

This article focuses on the taxonomy and anatomical reassessment of European Upper Jurassic stegosaurs, particularly the genus Dacentrurus armatus. Based on a newly described, relatively complete stegosaurian skeleton from the Villar del Arzobispo Formation in Spain and a comprehensive review of European material, the study finds high morphological homogeneity among specimens previously assigned to Dacentrurus armatus and the controversial taxon Miragaia longicollum. Consequently, Miragaia longicollum is proposed as a subjective junior synonym of Dacentrurus armatus, consolidating the European Late Jurassic stegosaurian fauna to two species: Dacentrurus armatus and Stegosaurus stenops. Additionally, the species longispinus from the Morrison Formation (USA) is reaffirmed as belonging to the genus Alcovasaurus, distinct from Dacentrurus. The study provides an updated diagnosis of Dacentrurus armatus based on autapomorphies from the holotype and referred specimens, enhancing understanding of its anatomy and intraspecific variation.