1 Faculty of Archeology, Leiden University, 2333 CC Leiden, The Netherlands; p.r.b.kozowyk@arch.leidenuniv.nl g.langejans@tudelft.nl g.l.dusseldorp@arch.leidenuniv.nl marcelniekus@gmail.com.
2 Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, 2628 CD Delft, The Netherlands; p.r.b.kozowyk@arch.leidenuniv.nl g.langejans@tudelft.nl g.l.dusseldorp@arch.leidenuniv.nl marcelniekus@gmail.com.
3 Palaeo-Research Institute, University of Johannesburg, Johannesburg 2092, South Africa.
4 Stichting STONE/Foundation for Stone Age Research in The Netherlands, 9741 KW Groningen, The Netherlands p.r.b.kozowyk@arch.leidenuniv.nl g.langejans@tudelft.nl g.l.dusseldorp@arch.leidenuniv.nl marcelniekus@gmail.com.