•Seriated bone harpoons are generally found below the watershed with the
sole exception of the Moroccan one
•This is treated by Yellen as typologically exceptional and moreover is
pre-Holocene
•It is suggested here that it is essentially unconnected with the harpoons typical of the aquatic
expansion
•The expansion of Nilo-Saharan would only have gone as far as the
‘watershed line’ as these specialised aquatic resource exploiters did not have
th technology to survive in the more arid region further north