Central America bioregion

The Central America bioregion is a biogeographic region comprising southern Mexico and Central America.
The bioregion covers the southern portion of Mexico, all of Belize, Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua, and all but easternmost Panama.
WWF defines bioregions as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."
The bioregion lies in the tropics, and is home to tropical moist broadleaf forests, tropical dry broadleaf forests, and tropical coniferous forests. The higher mountains are home to cool-climate montane forests, grasslands and shrublands.
Central America connects North America to South America. The land bridge was completed 2.8 million years ago, when the Isthmus of Panama was formed, linking the two continents for the first time in tens of millions of years. The resulting Great American Interchange of animals and plants shaped the flora and fauna of the Central America bioregion.
Large mammals include the white-lipped peccary "(Tayassu pecari)", Baird's tapir "(Tapirus bairdii)", white-tailed deer "(Odocoileus virginianus)", Central American red brocket "(Mazama temama)", Yucatan brown brocket "(Mazama pandora)", giant anteater "(Myrmecophaga tridactyla)", brown-throated sloth "(Bradypus variegatus)", jaguar "(Panthera onca)", cougar "(Puma concolor)", and ocelot "(Leopardus pardalis)".
Plants of South American origin came to dominate the tropical lowlands of Central America, as did South American freshwater fish and invertebrates. 95% of Central American freshwater fish are South American in origin, with only the Tropical gar "(Atractosteus tropicus)", three clupeids "(Dorosoma)", a catostomid "(Ictiobus)", and an ictalurid "(Ictalurus)" of North American origin.
The montane vegetation of the region is distinct from the lowland vegetation, and includes species with origins in temperate North America, including oaks "(Quercus)", Pines "(Pinus)" and alders "(Alnus)", as well as a some species with origins in temperate South America, including "Weinmannia" and "Drimys".