Megalodon was probably extinct long before a number of strange seals, walruses, manatees, porpoises, dolphins and whales disappeared about 1-2.5 million years ago. (Representative image) & nbsp | & nbspphoto credit: & nbspGetty Images
Washington: Megalodon – a giant predatory shark that has inspired numerous books and blockbuster movies ̵
Another recent study attempted to associate this extinction and that of other marine animals with a supernova known to have occurred at that time. Researchers at the University of Wisconsin Oshkosh in the US found that many had problems with individual fossil data in the study to estimate the extinction date.
The study, published in the Journal of Life and Environmental Sciences, showed all fossil deposits of O Megalodon from the densely sampled rock of California and Baja California, Mexico, to estimate extinction. The researchers found that real fossil deposits existed until the end of the early Pliocene epoch 3.6 million years ago.
All later fossils either had a poor data source and probably originated from other fossil sites or showed that they were removed from older deposits. Up to 3.6 million years ago O megalodon had a continuous fossil record on the west coast.
"Using the same global dataset as previous researchers, we thoroughly examined each occurrence of fossils and found that most of the data had multiple problems – fossils with data too young or inaccurate, misidentified fossils, or old data have been refined through improvements in geology, and we now know that the specimens are much younger, "said Sarah Boessenecker of the University of Leicester in the UK. 19659004] "After extensive adjustments to this global sample and the statistical re-analysis of the data, we found that the extinction of O-Megalodon must have occurred at least one million years earlier than previously noted," Boessenecker said.
This is a significant adaptation, since O megalodon had probably died out long before the disappearance of a series of strange seals, walruses, manatees, porpoises, dolphins and whales disappeared sometime around 1-2.5 millions of years ago.
"It used to be thought that the extinction of O-Megalodon is related to this mass extinction underwater – but in reality we now know that the two are not directly related to each other," Boessenecker said. It is also unclear whether this proposed mass extinction is actually an extinction, as marine mammal fossils between the ages of 1 and 2 million years are extremely rare, resulting in a two-million-year "shaky chamber".
"It is more likely that there was a period of fauna turnover (many species are dying out and many new species are emerging) rather than an immediate and catastrophic extinction caused by an astronomical catastrophe like a supernova," said Boessenecker.
Researchers speculate that competition with the newly developed modern Great White Shark (Carcharodon carcharias) is a more likely cause for the extinction of Megalodon. Great whites appear about 6 million years ago and only in the Pacific with jagged teeth; 4 million years ago they are finally found worldwide.