Basal thyreophoran osteoderm found in the Middle Jurassic of Luxembourg
A recent article by Delsate and colleagues (2018) describes one of the earliest thyreophoran remains in Europe. It is an osteoderm from the lower Bajocian of Luxembourg, found in the marls and limestone sequence of the Rumelange-Ottange Quarry, on the Luxembourg-French border. The specimen exhibits features that seem to suggest a closer affinity to basal thyreophoran, such as Scelidosaurus for instance, than to early ankylosaurs. The smooth external surface is a plesiomorphic condition, as well as the internal structure, which in this specimen is composed of a thin cortical layer covering an internal lattice of trabecular bone (Scheyer & Sander, 2004; Burns & Currie, 2014; Delsate et al. , 2018). However, histological studies were not conducted and therefore the isolated scute is at this point more definitely identified as belonging to basal thyreoporan, although a basal ankylosaur origin is not ruled out. A last interesting aspect is that the osteoderm was found in a
