The skeleton of the plate-toothed Placodus gigas represents the only skeleton of this marine reptile anywhere in the world. Its torso was reinforced by closely arranged ribs and gastralia (“ventral ribs”) as well as a series of round ossifications of the skin above the vertebral processes. Therefore, these marine predators could only use their legs for propulsion. In 1915, a fossil collector found skeletal remnants in a quarry near Heidelberg inside already broken-up gravel stones. All of the pieces that could be located were put together, and over a period of several years, the skeletal remains were painstakingly extracted from the hard rock and assembled into an entire skeleton.