<span>Guyots are seamounts that have built above sea level. Erosion by waves destroyed the top of the seamount resulting in a flattened shape. Due to the movement of the ocean floor away from oceanic ridges, the sea floor gradually sinks and the flattened guyots are submerged to become undersea flat-topped peaks.</span>
I only photographed my textbook but this page gives a lot of information about your question
Some of the most populous ones are the Guarani, Tikuna, makuxi. The majority of the tribes were assimilated in 2019-2010. The country is going through a fight in the courts with president Bolsonaro on the legitimacy of some of the smaller tribes, and the land they own.
They grow foods and tends livestock to provide for a family