Levallois is the name archaeologists have given to a distinctive flint knapping technique, which makes up part of the ancient Acheulean and Mousterian artifact assemblages.
The stone tool making technique involves flaking pieces off the edge of a large piece of flint until it is shaped like a turtle shell, and using the core to make tools. The Levallois technique is thought to have been used by Neanderthals in Europe beginning about 250,000 years ago, and then perfected during the Mousterian of 100,000 years ago.
levallois core
levaillois point
see movie on levallois technique