Brazil

It is considered the country with the greatest biodiversity of all countries in the world.

An excerpt from the article 31 facts about Brazil

It has the most known species of plants (55.000), freshwater fish (3000), and mammals (more than 689). It ranks third on the list of countries with the most bird species (1832) and second with the most reptile species (744).

Brazil is the second country with the most endemic species after Indonesia.