The explosion of gold from supernovas some 150 light-years from Earth, around 2.6 million years ago, would have led to the disappearance of large marine animals on Earth such as the megalodon, the largest shark to have ever lived in our oceans.
During the Pliocene epoch, 5.333 million to 2.58 million years ago, a strangely bright light had appeared in the sky. The strange light lasted a few weeks and perhaps a few months, explain American astrophysicist Adrian Melott of the University of Kansas.
In the space of a few hundred years, long after the dissipation of this light, a wave of cosmic energy from the explosion has reached the Earth and destabilized the atmosphere to the point of causing significant climate change.
Recent papers have revealed the presence of a radioactive isotope of iron in ancient deposits of the seabed; they provide strong evidence of a temporal connection with the explosion of supernovas.Adrian Melott, University of Kansas
Professor Melott can not say for sure if the cosmic tsunami is the result of one or more supernovas. He’s debating whether there has been a single supernova or rather a chain of supernovas. “I prefer to think of a combination of two, one more powerful and closer than the other,” he argues.
According to the hypothesis of the astrophysicist and Brazilian colleagues, the very architecture of the local Universe of our galaxy, the Milky Way, suggests that it was sculptured following a series of supernovas.
Be that as it may, the Earth has been covered with a layer of iron-60, and particles called muons have joined its surface, causing cancer and mutations, especially in large animals.
We have estimated that the rate of cancer increased by about 50% for an organism of the size of a human being. For an elephant or a whale, the dose of radiation increased even more.Adrian Melott, University of Kansas
The extinction of the Pliocene was concentrated in coastal waters, where large larger organisms received a greater dose of muon radiation.
“The damages caused by the muons extended to the organisms living in the first hundreds of meters of the oceans, becoming less serious at greater depths,” say the researchers.
Large marine animals living in shallow waters may have thus been condemned by supernova radiation. One of the best-known animal extinctions of this period is the megalodon (Carcharocles megalodon), which reaches the size of a bus.