Prior to European colonization in the late 19th century, Africa had a very long history of state building as well as a rich variety of social formations that were decentralized or stateless. Some of the first examples of state formation in human history developed in the Nile River valley in the 4th millennium BCE. Nevertheless, during most of Africa’s precolonial history, a significant portion of African people lived in small-scale, egalitarian societies in which government was more a matter of consensus among the entire adult population than rule by an elite few. One of the major contributions that historians of precolonial Africa have made is to demonstrate the enormous variety and complexity of precolonial African political systems and to challenge the notion that political complexity only exists in centralized states.
The answer is Fraternal twins. This twins usually don't look like exactly the same because they don't share the same genetic material, they can't be distinguished as twins. This type of twins grow and born together in the womb from a unique fertilized egg.