Mauritania and Morocco both claim the land. Before colonisation the territory had links to booth countries.
These are hard ti disentangle because of the nomadic nature of the inhabitants.
The quasi legal ties at the time were too Mauritania
there were no formal frontiers.
The Shinguitti were a people or nation and had a language
They had a system of laws and of government.
In the 19th century agreements about rescuing shipwrecked persons recognised Moroccan sovereignty all the way down the coast. The signatories to the said agreements included Spain, France, the United States and the United Kingdom.