people during the middle paleolithic, such as the neanderthals and middle paleolithic homo sapiens in africa, began to catch shellfish for food as revealed by shellfish cooking in neanderthal sites in italy about 110,000 years ago and middle paleolithic "homo sapiens" sites at pinnacle point, in africa around 164,000 bp.&lt;ref name="nytimes/10/08/07"&gt;&lt;/ref&gt; although fishing only became common during the upper paleolithic, fish have been part of human diets long before the dawn of the upper paleolithic and have certainly been consumed by humans since at least the middle paleolithic. for example, the middle paleolithic "homo sapiens" in the region now occupied by the democratic republic of the congo hunted large -long catfish with specialized barbed fishing points as early as 90,000 years ago. the invention of fishing allowed some upper paleolithic and later hunter-gatherer societies to become sedentary or semi-nomadic, which altered their social structures. example societies are the lepenski vir as well as some contemporary hunter-gatherers such as the tlingit. in some instances (at least the tlingit) they developed social stratification, slavery and complex social structures such as chiefdoms.