Take a ride on the way, way, way back machine to about 520 million years ago. The Cambrian Explosion—Earth’s biggest bang of biodiversity, when the variety of living things increased exponentially—was just wrapping up. Terrestrial plants and animals had not yet evolved so the land was still barren, but oceans teemed with life. Early arthropods, invertebrates with tough exoskeletons, were becoming fierce predators. Now meet the terror beasts who ate arthropods for breakfast (and lunch and dinner). Paleontologists working in Peary Land, the northernmost edge of Greenland, have found fossils…
