Scelidosaurus

Scelidosaurus harrisonii represents one of the most complete Early Jurassic dinosaurs ever discovered and holds a pivotal position in understanding thyreophoran evolution. This medium-sized, heavily-built herbivore possessed rows of bony osteoderms embedded in its skin, running along its back and flanks in parallel rows. These keeled scutes varied in size, with the largest positioned along the midline, providing substantial protection against predators of the Jurassic coastline.

The skull was small and narrow relative to its robust body, featuring a horny beak at the front and leaf-shaped teeth suited for processing vegetation. Its limbs were sturdy with the hindlimbs notably longer than the forelimbs, though the animal was predominantly quadrupedal. Some researchers suggest it may have been capable of occasional bipedal stance when browsing higher vegetation.

Discovered on the Dorset coast near Charmouth, the first Scelidosaurus specimens emerged from the Blue Lias Formation's marine clays, suggesting the carcasses were washed out to sea before fossilization. This taphonomic history explains the exceptional three-dimensional preservation. Despite being among the first complete dinosaurs found, it remained poorly understood for over 160 years until David Norman's comprehensive 2020 redescription. This landmark study confirmed Scelidosaurus as a basal thyreophoran, positioned near the base of the lineage that would eventually split into the plate-bearing stegosaurs and tank-like ankylosaurs.