Homo habilis
In 1960 and 1963 Louis Leakey and others found the possible first Homo in the Olduvai Gorge, Kenya with a more complete skull being found ten years later by his son Richard at Lake Turkana.
These and later finds in Kenya are much debated. Many palaeoanthropologists acknowledge two species Homo habilis (handyman - agile hands and 600-700cm3 brain volume) and Homo rudolfensis with an even larger brain but other more primitive skull features.
Both are dated to 2.4-1.5 Myr ago and have been found associated with various australopiths. This conjures up the striking notion of four or five different human species living side by side.