Trilobites are one of the most important sea creatures that lived in the Cambrian Period, leaving many traces in various parts of the world. One of the most astounding features of trilobites is their multi-lensed eye structure, consisting of countless units, each one of which is a lens. Just as the hexagonal "honeycomb" eyes of insects, each of these units functions as a single, independent lens. Each one perceives a separate image, and in the brain, these images unite into a whole. Research shows that some trilobites" eyes have more than three thousand lenses, which means that more than three thousand images are conveyed to this crustacean. In short, a sea creature that lived 380 million years ago had a highly complex brain and eye—flawless structures that could not have come into being by evolution.