Great thread Satanus.
Whilst no doubt the indigenous tribes of each country might have differed a number of striking similarities are evident, their respect for the land and nature, their deep respect and even awe for women especially their childbearing 'powers'.
Their following the seasons closely and the festivals attached to significant points in the year were similar, they believed in life, death and rebirth. Their close observance of the heavens and the stars and reverence in particular for the Moon and Sun are also evident within most indigenous tribes in many countries.
The original religion evolved from there - somehow we lost our way from the land and slowly but surely many are finding their way back.
Gary