the stone tool kit of archaic hominids as impossible to categorize. He argues that almost everywhere, whether Asia, Africa or Europe, before 50,000 years ago all the stone tools are much alike and unsophisticated. Firstly among the artefacts of Africa, archeologists found they could differentiate and classify those of less than 50,000 years into many different categories, such as projectile points, engraving tools, knife blades, and drilling and piercing tools. These new stone-tool types have been described as being distinctly differentiated from each other; each tool had a specific purpose. The early modern humans who expanded into Europe, commonly referred to as the Cro-Magnons, left many sophisticated stone tools, carved and engraved pieces on bone, ivory and antler, cave paintings and Venus figurines. The Neanderthals continued to use Mousterian stone tool technology and possibly Châtelperronian technology. These tools disappeared from the archeological record at around the same time the Neanderthals themselves disappeared from the fossil record, about 40,000 cal BP. Settlements were often located in narrow valley bottoms, possibly associated with hunting of passing herds of animals. Some of them may have been occupied year round, though more commonly they appear to have been used seasonally; people moved between the sites to exploit different food sources at different times of the year. Hunting was important, and caribou/wild reindeer "may well be the species of single greatest importance in the entire anthropological literature on hunting". Technological advances included significant developments in flint tool manufacturing, with industries based on fine blades rather than simpler and shorter flakes. Burins and racloirs were used to work bone, antler and hides. Advanced darts and harpoons also appear in this period, along with the fish hook, the oil lamp, rope, and the eyed needle. Fishing of pelagic fish species and navigating the open ocean is evidenced by sites from Timor and Buka (Solomon Islands). The changes in human behavior have been attributed to changes in climate, encompassing a number of global temperature drops. These led to a worsening of the already bitter cold of the last glacial period (popularly but incorrectly called the last ice age). Such changes may have reduced the supply of usable timber and forced people to look at other materials. In addition, flint becomes brittle at low temperatures and may not have functioned as a tool. Notational signs Some notational signs, used next to images of animals, may have appeared as early