The earliest evidence of human life in Uzbekistan dates back to the Stone Age, or middle paleolithic. These are petroglyphs, burials, and temporary settlements discovered by archeologists. The people living in the middle paleolithic hunted wild goats, leopards, wild boars, and other animals. These people also gathered the roots and fruits of wild plants. They used fire: hearths made of stone were found inside the dwellings. The men made their tools of stone using the split-off method, applied to siliceous limestone, quartzite, and jasper. Among these finds are stone plates, arrowheads, scrapers and axes, and wooden and bone articles. Bent skeletons encircled by goat horns and the like, found in graves, show how the thinking of the primitive men developed.