I might be mistaken but the footage u have provided links to is of fights organised under Rio Heroes which is a modern MMA organisation.
Not my friend ! this is not in Rio and they are not organisation ! It happen at Sao Paulo City and there is not MMa organisation under it, just someone that want to make money with thoses figthers!
Of course various vale tudo fights happened before but this video shows the times when all those messy and clandestine fights became sport - with proper places, prizes, rules.. I was maybe 10 ten years old and I remember the great discussion in the media and society. Nice to look at those scenes again;)