Neanderthals selected rib bones from specific animals to make the lissoirs (French for 'smoothers'), which are bone tools that have been intentionally shaped and used on animal hides to make them softer and more water resistant, according to new research led by paleoanthropologists from the University of California, Davis. Scientists know that some Neanderthals produced bone tools. These include the discovery of five nearly identical fragments of lissoirs from two Paleolithic sites in southwest France: Pech-de-l'Azé I (Pech I) and Abri Peyrony. These specialized tools are often worn so smooth that it's impossible to tell which animal they came from...