OK, this whole thread is nonsense.
-What allowed most ancient and early modern civilisations to develop was not horse, rhino or any other animal but SHIP.
-Ancient civilisations appeared along waterways: rivers, seas, later even oceans, not along inland routes.
-Until railroad most of the transport and trade was done by SHIP not horse, rhino or pigeon.
-Until railroad, water was mean of transport and communication and land was obstacle.
-Africa newer was single civilisation. North Africa and Sub-Saharan Africa were always (or at last as long as we have some records) two different worlds. North Africa was always and till this day is part of "Mediteraean" and "Middle-Eastern" "world", civilisation or civilisations. Libya or Egypt are culturally, economically, politicaly even racially more close to Greece than to Kongo.