Although many believe that Homo habilis is the first ancestor of Homo erectus, the introduction of the skull of Dmanisi 5 and WT 15000 into the evolutionary lineage brings out results different. Skull Dmansi 5 and WT 15000 are classified as more closely related ancestors of Homo erectus, especially since they share many characteristics. Homo erectus is of interest to many scientists because it is considered the probable ancestor of modern humans given that its fossils differ from those of ape-man or Homo habilis. This article focuses on identifying the true or direct ancestor of Homo erectus. After comparing Homo erectus with Dmanisi and Homo erectus with WT 15000, this article reveals that the Homo erectus and WT 15000 papers share many characteristics, making WT 15000 the direct ancestor of Homo erectus. At the same time, Homo erectus fossils were found in East Africa, Dmanisi fossils were found in Eastern Europe in the Republic of Georgia, and the Turkana boy or Nariokotone was found in the west from Lake Turkana in Kenya (Hazarika, 2007). These discoveries, however, did not all concern Homo erectus but ...