You are in the coastal lagoons of Europe, 191 million years ago.

The humid air of the Early Jurassic clings to your skin, smelling faintly of cycads and sulfur, as you step out from the lush ferns onto a tidal mudflat near what will eventually be Dorset, England. The ground is soft, making your footsteps silent.

Before you, a herd of Scelidosaurus—perhaps a dozen—are browsing on the low-lying coastal vegetation. They are smaller than you imagined, maybe 12 to 13 feet long, but their backs are a striking sight: rows of bony, oval scutes, or osteoderms, that look like polished pebbles or dark, thorny shields.

One of them, a mature individual, pauses, its head—elongated and relatively small—lifting from the ferns. Its large, dark eye locks onto you. It doesn’t seem panicked, just cautious. The dinosaur is primarily quadrupedal, standing firm on all four legs, which are heavily built. The skin on its neck and sides seems textured, with some scutes looking almost metallic in the damp sunlight.