Scientists just named a new species of ancient, 'megatoothed' shark

Scientists have named a new species of shark that likely stalked the Atlantic and Pacific coastlines some 20 million years ago.

Megalolamna paradoxodon, now extinct, had left few clues of its long-ago existence.

Researchers found just five of the species' mega-sized teeth at sites in Japan, California, Peru and North Carolina, according to a study published this week in the journal Historical Biology.

The chompers measured nearly 2 inches long, suggesting the shark could have grown to be up to 12 feet long. The great white shark, by comparison, can reach lengths of up to 20 feet.

A great white shark photographed on September, 8, 2015 near Guadalupe Island, Mexico. Credit: David Fleetham / Barcroft India / Barcroft Media via Getty Images

The shark's genus name, Megalolamna, refers to its large teeth (from the Greek "megas," or great) and also hints at the teeth's resemblance to those of known sharks in the Lamna genus, according to the study led by Kenshu Shimada, a paleobiologist at DePaul University in Chicago.

The species name, paradoxodon, combines the Latin word "paradoxum," or paradox, with the Greek word "odon," or teeth.

The sharks likely lived in shallow coastal waters in the mid-latitudes and feasted on prey such as medium-sized fish, researchers said.

Original image has been replaced. Credit: Mashable

Shimada said his research team initially thought the shark's gigantic teeth could be from the Lamna genus, which includes the modern porbeagle and salmon sharks.

"However, the fossil teeth are too robust for Lamna -- it shows a mosaic of dental features reminiscent of the genus Otodus," Shimada told Live Science.

"So, we determined it to be a species new to science that belongs to the family Otodontidae, with no direct relationship with Lamna," he told the science news site.