The Amazon is a neighborhood of stupefying innate looker and unbelievable biodiversity . And its history might be just as colorful . According to a new study , published inScience Advances , the Amazon sank twice , with the Caribbean flood the region and creating a shallow ocean .
The late finding will emphatically make an intense debate , as there is no consensus on how the Amazon issue forth to organise . The squad from the Smithsonian Tropical Research Institute have analyze over 50,000 pollen grains from oil drilling cores and have found a tiny shark tooth , part of a mantis shrimp , and marine micro-organism . The team is sure-footed that this is enough to make their case .
" Pollen records from oil wells in eastern Colombia and outcrops in northwestern Brazil clearly show two short - lived upshot in which ocean water from the Caribbean flooded what is now the northwest part of the Amazon drainage basin , " said lead generator Carlos Jaramillo in astatement . " Geologists take issue about the ancestry of the sediments in this surface area , but we furnish clear evidence that they are of marine origin , and that the flooding case were fairly brief . "
The two flooding events materialise between 18 and 17 million old age ago and between 16 and 12 million years ago . They established this using the pollen . The squad found two layer of marine pollen types tell by a layer of non - nautical ones . They prove 900 types of pollen from the deposit to make that assessment .
There are , of track , other possibility . The region could have had a mammoth freshwater lake or a complex , shifting organisation of river . ocean urine incursions might have been mutual and get contaminations now seen in the dodo record . datum from more emplacement is plausibly necessary to touch a consensus .
These important geologic changes appear to have bechance just before ( in geological terms ) the shaping of the Andes , which form between10 and 6 million years ago . scientist think that the enigma to the incredible diversity of life forms in the region is due to its complex past times .
" It ’s important to understand changes across the immense Amazonian landscape that had a unfathomed effect , both on the evolution and distribution of life there and on the mod and ancient climates of the continent , " Jaramillo added .
The Amazon rain forest is about the size of it of the United States and is the tumid rainforest on Earth . It holds10 percentof all species living on the planet .
