Several archaeological finds from Europe also support the interpretation of increased behavioral sophistication in H. heidelbergensis . The site of Boxgrove in England (dated to roughly 500 kya) has yielded thin, extensively flaked flint bifaces (a stone tool which is produced by removing flakes of stone from both sides) along with cut-marked bones of horses and rhinos. A large, robust hominin tibia (., shin bone), attributed by some to H. heidelbergensis has also been recovered at Boxgrove. In Germany, the site of Schöningen (dated to roughly 400 kya) has yielded three wooden spears associated with flint tools and chips. Similar sites in Spain, France and Italy also yield Late Acheulean tools associated with large herbivore bones. Together, these finds are evidence that H. heidelbergensis may have hunted and butchered large game, an activity that requires experience, practice and cooperation. Based on archaeological evidence, H . heidelbergensis had increased levels of social cooperation.