tool industry of the coastal regions of northern Europe, dating from about 9000 to 3500 BC. The Ertebølle industry, named after Ertebølle, Den., where it was first recognized, is classed as a Mesolithic (Middle Stone Age) industry because its people used chipped, rather than polished, stone tools and because they were hunters and fishers rather than agriculturists, who used polished stone tools in the developing agriculture of the Neolithic Period (New Stone Age). The Ertebølle industry had in many ways, however, borrowed from Neolithic industries of central Europe, which were partly contemporaneous with it. The Ertebølle culture, known from its kitchen middens, or garbage heaps, had pottery, chisel-shaped arrowheads, flat and radial flaking techniques for working flint, and, toward the end of the period, some agriculture and stock raising—all Neolithic skills.