Update of this post: http://the-arc-ddeden.blogspot.com/2007/12/aechulian-hand-axe-or-bifacial-bait.html
What exactly were Acheulian "hand-axes" (with their very specific forms) for?--marc
DDeden: multi-functional knives, including use as predator bait traps, inserted into flesh of prey and set at waterside to kill crocs, sharks, wolves, lions, etc. They are most commonly found near former waterside areas, (per Mikey Brass at Paleoanthro) they were made with sharp edges all around (so inconvenient for handling unless partly covered), swallowed by predators that had a habit of 'wolfing' down chunks of flesh quickly.
Why Did Early Humans Leave Africa Without the Latest Gadgets?Brian Switek 31.8.11In ancient sediments near Kenya's Lake Turkana, archaeologists have foundstone hand axes dating to 1.76 Ma - the oldest examples yet found of theAcheulian stone-tool technology.People love to get their hands on the latest & greatest technology, andscientists had long believed that early humans were no exception.Paleontologists theorized that our ancestors didn't start leaving Africauntil they had developed advanced hand axes.But a new study finds that early humans began to migrate out of thecontinent with more primitive tools, even though better technology hadbeen invented. Over time, various groups of ancient humans have made various types ofstone tools. The oldest & most rudimentary instruments (sharp-edged stones created bybanging rounded rocks against larger stone "anvils") belong to the Oldowanculture ~2.6-1.7 Mao.From the Oldowan, a more complex tool culture developed called theAcheulian ~1.6 Ma. These are more complicated tools, such as teardrop-shaped hand axes,created by striking carefully selected stones with other rocks calledhammer-stones. These tools were useful for a wider range of tasks than the Oldowan ones.It was the Acheulian culture that first spread farthest around the globe,and it persisted until ~100 ka.