A supernova that took place some 150 light years away from Earth could have sent off a tsunami of cosmic energy that eventually stormed through the earth’s atmosphere triggering climate change and mass extinctions of large marine species such as Megalodon.
According to Adrian Melott, the lead of the paper, and his team, the supernova energy scattered layers of iron-60 all over the world and it caused high energy particles called muons to spread throughout the earth causing cancers and mutations particularly to larger animals.

The detrimental effect of high energy muons extended down hundreds of yards into ocean waters and became less severe with depths which may explain the doom of a famously large and fierce marine animal inhabiting shallower waters.
“One of the extinctions that happened 2.6 million years ago was Megalodon,” Melott said. “Imagine the Great White Shark in ‘Jaws,’ which was enormous– and that’s Megalodon, but it was about the size of a school bus. They just disappeared about that time. So, we can speculate it might have something to do with the muons. Basically, the bigger the creature is the bigger the increase in radiation would have been.”
The horrific consequences of such a supernova – and possibly more than one – on large ocean animals have been discussed in a paper published in Astrobiology.
Source: University of Kansas