Final answer:
The 'Nariokotome Boy' is the most significant H. erectus fossil found at East Turkana, dating back to 1.8 mya, making it the oldest known H. erectus specimen.
Step-by-step explanation:
The most significant H. erectus fossil from East Turkana is a nearly complete specimen known as the Nariokotome Boy. Dated at 1.8 mya this is the oldest H. erectus specimen ever found. Homo erectus, first appearing around 1.9 million years ago in East Africa, was larger than earlier hominins and exhibited physical features and behavioral patterns more akin to modern humans. Not only did this species have a larger brain, but it also showed evidence of tool use, hunting, and possibly the controlled use of fire. The discovery of fossils like the Nariokotome Boy helps to shed light on the evolution and dispersal of Homo erectus from Africa to other parts of the world.