It is sometimes used as a synonym for the tropical area of South America, although the ecozone also includes temperate southern South America. Its fauna and flora are distinct from the Nearctic (which includes most of North America) because of the long separation of the two continents. The formation of the Isthmus of Panama joined the two continents 2 to 3 million years ago.
The Neotropic includes more tropical rainforest than any other ecozone. They extend from southern Mexico through Central America and northern South America to southern Brazil and include the Amazon Rainforest. These rainforest ecoregions are one of the most important reserves of biodiversity on Earth. Extensive deforestation in the late 20th century has reduced this diversity to a degree.
- Cox, C. Barry; Peter D. Moore 1985. Biogeography: an ecological and evolutionary approach. 4th ed, Blackwell Scientific Publications, Oxford.
- Dinerstein, Eric; David Olson; Douglas J. Graham; et al. 1995. A conservation assessment of the terrestrial ecoregions of Latin America and the Caribbean. World Bank, Washington DC.
- Schultz J.: 2005. The Ecozones of the World. 2nd ed, Springer, Berlin Heidelberg New York. ISBN 3-540-20014-2
- Udvardy M.D.F. 1975. A classification of the biogeographical provinces of the world. IUCN Occasional Paper #18. Morges, Switzerland: IUCN.