The ancient Otodus megalodon, the largest shark to ever swim in our planet’s oceans, still inhabited the sea up to around 3.6 million years ago. The exact cause of the species’ extinction is still debated, likely a combination of environmental change and competition with smaller shark species played a role.
Despite its fame in pop-culture, surprisingly little is known about the life-appearance of the megalodon. Sharks have only a cartilaginous skeleton that quickly decays after death, only their hard teeth survive the long and ardeous fossilization process. Megalodon was formerly thought to be a close relative of the great white shark (Carcharodon carcharias) based on similarities observed between fossil teeth and current-day Carcharodon teeth. The great white shark often measures more than 19 feet (or 6 meters) in length. So megalodon was depicted as a very big white shark with length estimates ranging from 80-100 feet (25-30 meters). However, it is now classified into the extinct family Otodontidae, which diverged from the great white shark lineage during the Early Cretaceous, some 100 million years ago. As the two species are not closely related, the teeth – body size relationship of C. carcharias alone can’t be used to reconstruct the body size of the extinct relative.