This trilobite lived in very large numbers in what is now Sweden in the Middle Ordovician period. It was probably a scavenger, feeding on dead animals such as big cephalopods on the sea floor.
Like most trilobites, Asaphus had a hard, segmented carapace (shell) on its back and a softer underside, with many legs. In danger, it could roll up into a ball to protect its belly and vulnerable legs. Trilobites were often buried in this rolled-up state.