Homo erectus adult female - head model - Smithsonian Museum of Natural History - 2012-05-17
A model of the face of an adult female Homo erectus, one of the first truly human ancestors of modern man, on display in the Hall of Human Origins in the Smithsonian Museum of Natural History in Washington, D.C.
Homo erectus lived between 1.8 to 1.3 million years ago. It's not clear who its own ancestor was. It could be a descendant of Homo ergaster (in which case its descendants are Homo heidelbergensis, Homo neanderthalensis, and Homo sapiens) or that it evolved from an unknown ancestor in Asia. It was discovered on the island of Java in 1891 by Eugène Dubois. (It was initially known as "Java Man.")
Their brains varied in size, with earlier specimens and specimens in distinct sub-populations having slightly smaller brains than Homo sapiens, and others being just slightly larger! They stood about 5'10", and were more muscular than modern humans.
Homo erectus had a forehead that was less sloped backward than previous human ancestors, and the teeth did not protrude as much. But it had strong eyebrow ridges and sunken cheekbones.
Homo erectus was probably the first human ancestor to form a hunter-gatherer society. there is good evidence that it hunted in groups, and cared for the sick, injured, or weak. It used slightly more sophisticated stone and wood tools than its ancestors, although there is still debate about how capable it was of producing vocal sounds or even language.