Central American seaway

The Central American seaway was an ancient seaway that separated North and South America for much of the Paleogene and Neogene periods. This separation allowed the faunas of the two continents to evolve independently. The Isthmus of Panama, which formed this seaway, was submerged for millions of years. It was only during the Pliocene Epoch, approximately 5.3 to 2.6 million years ago, that the isthmus was elevated for periods, creating a land bridge. This land bridge allowed for the migration of species between the two continents, profoundly impacting the fauna of the New World. The marine faunas of the eastern Pacific and western Atlantic were similar until about 3 to 5.5 million years ago when the elevation of the Central American isthmus created a land barrier, leading to the isolation and differentiation of these faunas.12