A spear is a pole weapon consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with fire hardened spears, or it may be made of a more durable material fastened to the shaft, such as bone, flint, obsidian, iron, steel, or bronze. The most common design for hunting or combat spears since ancient times has incorporated a metal spearhead shaped like a triangle, lozenge, or leaf. The heads of fishing spears usually feature barbs or serrated edges. The word spear comes from the Old English spere, from the Proto-Germanic speri, from a Proto-Indo-European root *sper- "spear, pole". Spears can be divided into two broad categories: those designed for thrusting as a melee weapon and those designed for throwing as a ranged weapon (usually referred to as javelins or darts). The spear has been used throughout human history both as a hunting and fishing tool and as a weapon. Along with the club, knife, and axe, it is one of the earliest and most important tools developed by early humans. As a weapon, it may be wielded with either one or two hands. It was used in virtually every conflict up until the modern era, where even then it continues on in the form of the fixed bayonet on a long gun, and is probably the most commonly used weapon in history. Origins Spear manufacture and use is not confined to humans. It is also practiced by the western chimpanzee. Chimpanzees near Kédougou, Senegal have been observed to create spears by breaking straight limbs off trees, stripping them of their bark and side branches, and sharpening one end with their teeth. They then used the weapons to hunt galagos sleeping in hollows. Prehistory Archaeological evidence found in present-day Germany documents that wooden spears have been used for hunting since at least 400,000 years ago, and a 2012 study from the site of Kathu Pan in South Africa suggests that hominids, possibly Homo heidelbergensis, may have developed the technology of hafted stone-tipped spears in Africa about 500,000 years ago. Wood does not preserve well, however, and Craig Stanford, a primatologist and professor of anthropology at the University of Southern California, has suggested that the discovery of spear use by chimpanzees means that early humans may have used wooden spears before this. Neanderthals were constructing