New research suggests the megalodon shark became extinct around 2.6 million years ago, squashing claims that it is still alive.
The shark was the largest to ever live, and studying its existence could provide insight into potential effect of the loss of the world's larger predators, the University of Florida reported.
"I was drawn to the study of Carcharocles megalodon's extinction because it is fundamental to know when species became extinct to then begin to understand the causes and consequences of such an event," said lead author Catalina, a doctoral candidate at the Florida Museum of Natural History on the UF campus. "I also think people who are interested in this animal deserve to know what the scientific evidence shows, especially following Discovery Channel specials that implied megalodon may still be alive."
Modern large predators such as sharks are rapidly declining, and these findings could help measure the related consequences imposed on the ecosystem.
"When you remove large sharks, then small sharks are very abundant and they consume more of the invertebrates that we humans eat," Pimiento said. "Recent estimations show that large-bodied, shallow-water species of sharks are at greatest risk among marine animals, and the overall risk of shark extinction is substantially higher than for most other vertebrates."
When the research team calculated the time of the megaladon's extinction, they found giant feeder whales became established around the same time; in the future they plan to look at if the ecological changes caused the whales to evolve.
To make their findings the researchers used databases and scientific literature of the most recent megalodon records and used a mathematical model to determine when they became extinct.
"The methodology that the authors used had only been previously employed to determine extinction dates in historical times, such as to estimate the extinction date of the dodo bird," Jorge Velez-Juarbe with the Natural History Museum of Los Angeles County said. "In this work, scientists applied that same methodology to determine the extinction of an organism millions of years ago, instead of hundreds. It's a new tool that paleo biologists didn't have, or rather had not thought of using before."
The findings were published Oct. 22 in the journal PLOS ONE.