a ▁were ▁transferred ▁to ▁bas al ▁groups ▁within ▁Dia ps ida ▁( such ▁as ▁Pala e ag ama ▁and ▁Sau rost ern on ), ▁ ▁Arch osa ur om or pha ▁( T an yst rop he us ▁and ▁C ten i ogen ys ) ▁and ▁even ▁Sau rop od om or pha ▁( F ul eng ia ). ▁ ▁References ▁▁ ▁Category : Pre histor ic ▁re pt iles ▁Category : E ar ly ▁Tri ass ic ▁first ▁appearances ▁Category : L ate ▁Tri ass ic ▁ext in ctions <0x0A> </s> ▁The ▁earliest ▁humans ▁were ▁h unter ▁gather ers ▁who ▁were ▁living ▁in ▁small , ▁family ▁group ings . ▁Even ▁then ▁there ▁was ▁considerable ▁trade ▁that ▁could ▁cover ▁long ▁distances . ▁Arch ae olog ists ▁have ▁found ▁that ▁evidence ▁of ▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁ ▁▁▁▁ ▁trade ▁in ▁lux ury ▁items ▁like ▁pre cious ▁met als ▁and ▁shell s ▁across ▁the ▁entire ty ▁of ▁the ▁continent . ▁ ▁African ▁economic ▁history ▁often ▁focus es ▁on ▁explan ations ▁of ▁pover ty ▁and ▁obsc ures ▁other ▁aspects ▁such ▁as ▁the ▁achiev ements ▁of ▁African ▁far mers , ▁trad ers ▁and ▁states , ▁including ▁improvements ▁in ▁food ▁security , ▁and ▁episodes ▁of ▁economic ▁growth . ▁ ▁An cient ▁history ▁Africa ▁has ▁the ▁longest ▁and ▁oldest ▁economic ▁history . ▁As ▁soon ▁as ▁human ▁soci eties ▁came ▁into ▁existence , ▁so ▁did ▁economic ▁activity . ▁Ear liest ▁humans ▁were ▁h unter ▁gather ers ▁living ▁in ▁small , ▁family ▁groups . ▁Even ▁then ▁there ▁was ▁considerable ▁trade ▁that ▁could ▁cover ▁long ▁distances