A series of industries in the coastal regions of West Africa during the last 10,000 years. Backed microliths akin to those manufactured in earlier times are associated with pottery and with ground stone ax- and hoe-like implements. One of the few well-described and dated occurrences is at Bosumpra near Abetifi in Ghana, where the occupation is dated between the 4th-2nd millennia BC. Because most of these peoples were nonliterate, there are few records up to c 1000 AD, when Arab historians began describing the western African region. By that time, it already had centralized states, agriculture, and long-distance trading routes.