Saturday, 3 September 2011

Advanced Stone Tools Are 300,000 Years Older Than Previously Thought

Kokiselei stone tools. the white bars represent 5 millimetres
Stone hand axes are a type of tool which is usually pear shaped, ranges in sizes from hand size to the size of a large knife, have a sharp point and one or two sharp edges used for cutting. These appeared first in what is known as the Acheulean stone tool industry around 1.4 million years ago. These were created by our early hominid ancestor Homo erectus. They show that early humans had developed advanced enough cognitive functions to be able to shape stone with tools to make new tools.

However a team of researchers have discovered a hoard of Acheulean stone tools which date to 1.76 million years old, pushing the Acheulean industry back 300,000 years. Similar tools appear from dates around 1.8 million years ago. However these are part of the sub Oldowan industry, rather than their more advanced Acheulean descendants. 'We suspected that Kokiselei was a rather old site, but I was taken aback when I realised that the geological data indicated that it was the oldest Acheulean site in the world' said the study's lead author Christopher Lepre, a geologist with joint positions at the Rutgers and Lamont-Doherty Universities.

Homo erectus was the first hominid to spread out of Africa. This is interesting as they did not take this new Acheulean stone tool kit with them despite the fact that it was very advanced for its time. They eventually hit an evolutionary dead end and died out. The team are currently making excavations at older sites to try and find out more about Oldowan stone tools.