Why Did Megalodon Go Extinct?
The giant shark Megalodon, which grew to around 60 feet long but went extinct a couple million years ago, may have taken a risky evolutionary approach to its hugeness.
Researchers recently rewound evolution in computer models to find two likely paths to gigantism: become a filter feeder (like the similarly sized modern whale shark or the blue whale, the largest animal that ever lived); or evolve adaptations to cold water, such as controlling body temperature to some degree, to allow a wider range of hunting grounds and to hunt more effectively.
Meg apparently followed the later approach, called mesothermic adaptation, at its own peril.
The study, led by Catalina Pimiento at Swansea University in the UK, is detailed in the journal Evolution.
“The mesothermic species need to consume big prey to maintain their high energetic demands, but when these prey are scarce, giant sharks are more susceptible to extinction,” Pimiento and colleagues said in a press release today. “The scarcity of large prey in times of rapid climatic change was the most likely cause of the extinction of Megalodon,” factors that Pimiento has previously shown.
But the filter feeders face risks, too, in part thanks to you and me.
“They are at risk of eating large volumes of toxic micro plastics [found in everything from chewing gum to facial scrubs] that now can be found in the world’s oceans — thus threatening their extinction,” the researchers say.
