Remains of Homo Ergaster have been excavated at Lake Turkana –
Homo ergaster (meaning “working man”) or African Homo erectus is an extinct chronospecies of Homo that lived in eastern and southern Africa during the early Pleistocene, between 1.8 million and 1.3 million years ago. There is still disagreement on the subject of the classification, ancestry, and progeny of H. ergaster, but it is now widely accepted to be the direct ancestor of later hominids such as Homo heidelbergensis, Homo sapiens, and Homo neanderthalensis and Asian Homo erectus.
It is one of the earliest members of the genus Homo, possibly ancestral to, or sharing a common ancestor with, Homo erectus. Some paleoanthropologists consider H. ergaster to be simply the African variety of H. erectus; this leads to the use of the term “Homo erectus sensu stricto” for the Asian H. erectus, and “Homo erectus sensu lato” for the larger species comprising both the early African populations (H. ergaster) and the Asian populations. The latest discoveries go even further claiming that all five contemporary species of early “Homo” in Africa, “Homo habilis”, “Homo rudolfensis”, “Homo ergaster”, and “Homo erectus” are representatives from the same species, best named “Homo erectus” who evolved about 2 million years ago in Africa and expanded through Eurasia, as far as China and Java, where it was first documented from about 1.2 million years ago. The binomial name was published in 1975 by Groves and Mazák. The second part, “ergaster”, is derived from the Ancient Greek ἐργαστήρ “workman”, in reference to the comparatively advanced lithic technology developed by the species, introducing the Acheulean industry.