The largest known shark known to have lived, Megalodon, had teeth that were unlike those of any living animal, according to new research.
Large and powerful Megalodon, which grew up to 66 feet long, flashed teeth that were heavily comprised of fluoride, the new study determined. Modern sharks only have fluoride on the surface, or enamel, of their teeth. The findings are published in the journal RSC Advances.
"You might say that they also used ‘built-in toothpaste,'" senior author Matthias Epple, a professor at the University of Duisburg-Essen's Institute of Inorganic Chemistry, told Discovery News.
"The ‘built-in toothpaste' refers to the fluoride content," he said, adding that Megalodon never suffered from cavities.
This, however, was primarily because the enormous shark had a "revolving jaw" that regularly replaced any teeth that went missing, maybe left behind in prey. Today's great whites and other sharks benefit from such a replacement system too.
Megalodon teeth were almost 8 inches long, making them much larger than those of any living shark. Now extinct, Megalodon is thought to have terrorized ocean dwellers from around 16 to 2 million years ago.