Mega diversity means exhibiting great diversity. The main criteria for megadiverse countries is endemism at the level of species, genera and families. A megadiverse country must have at least 5,000 species of endemic plants and must border marine ecosystems.
In 2002, Mexico formed a separate organisation focusing on Like-Minded Megadiverse Countries, consisting of countries rich in biological diversity and associated traditional knowledge. This organisation does not include all the megadiverse countries as identified by Conservation International.