Origin of mangroves & mangrove diversity
Scientists theorize that the earliest mangrove species originated in the Indo-Malayan region, where there are far more mangrove species than anywhere else in the world.
Because of their unique floating propagules and seeds, certain of these early mangrove species spread westward, borne by ocean currents, to India and East Africa, and eastward to the Americas, arriving in Central and South America between 66 million years ago (upper Cretaceous period) and 23 million years ago (lower Miocene epoch).
During that time, mangroves spread throughout the Caribbean Sea across an open seaway which once existed where Panama lies today.
Later, sea currents may have carried mangrove seeds to the western coast of Africa and as far south as New Zealand. This might explain why the mangroves of West Africa and the Americas contain fewer, but similar colonizing species, whereas those of Asia, India, and East Africa contain a much fuller range of mangrove species.