
Acuri palm nuts
Not the greatest photo but I wanted to share this for educational purposes. These are the fruits of the Acuri Palm, omnipresent in the Pantanal, and the main diet for almost all monkeys and parrots.
These nuts are hard as stone. You cant put a dent in it with your bare hands, you can barely damage it by hitting it on stone either. Yet, both cappuchin monkeys and parrots have no trouble opening them.

"Attalea phalerata" is a species of palm tree. It is native to Brazil, Bolivia, Paraguay, and Peru, where it grows along southern and western Amazonia. It is the most common palm tree on the Pantanal.