These crude tools were around for thousands of centuries, until around 1.4 million years ago when Homo erectus started shaping single, thin stone blades, sometimes rounded ovals, but often in what are to our eyes an arresting, symmetrical pointed leaf or teardrop form.
Ovi grubi alati služili su hiljadama stoleća sve dok pre milion i četiristo hiljada godina homo erektus nije počeo da oblikuje jednostruka sečiva od tankog kamena, ponekad zaobljene ovale, ali najčešće takvog oblika koji na s podseća na upečatljiv oblik simetričnog šiljatog lista ili na oblik suze.