The Megalodon, a giant shark now extinct

The natural cycle of life is movement. Also, the extinction of a species, which consists in the total disappearance of the animals representing it, is a phenomenon regularly observed throughout the geological life of the planet. The most famous example is the disappearance of dinosaurs. But many other species, perhaps less popular, have also disappeared, including the Megalodon which interests us in this article, considered to be the largest predatory fish to have ever existed on Earth.

Who was the Megalodon?

The only traces of the Megalodon (Otodus megalodon) that have come down to us are teeth (which, when fossilized are called glossopeters), with a dimension ranging between 12 and 18 cm, and some vertebrae, which is very rare because the skeleton of the Megalodon was made up of cartilage and not of bones, like the fish we know today, material which disintegrates very quickly after the death of the animal.

The Megalodon is a shark attached to the order Lamniformes whose characteristics are as follows:

  • 2 dorsal fins,
  • An anal fin,
  • 5 gill slits,
  • Eyes without a protective membrane,
  • A mouth extended behind the eyes.
  • The animal liked warm waters. Also, it would not have managed to withstand the oceanic cooling associated with the onset of the ice ages,
  • The sea level has fallen, causing the reduction and then the complete disappearance of its breeding areas,
  • A decrease in the populations of baleen whales, the main food source of the Megalodon.

The hypothesis that the Megalodon is part of the Lamnidae family first prevailed. From this point of view, the Megalodon is considered to be the giant ancestor of the current white shark, the reduction in size having occurred due to the scarcity of food. Today, another hypothesis exists and seems to predominate, eliminating the previous one: the Megalodon would be part of the extinct family of Otodontidae. Be that as it may, the kinship relationships of this shark with other species are still far from clear.

What did the Megalodon look like?

The first reconstruction of the Megalodon jaw dates from 1909. Carried out by the American Museum of Natural History, it turned out to be erroneous. The year 1991 marks the first European reconstruction, carried out for the Bioparc de Doué-la-Fontaine from teeth found in sedimentary deposits in Angevin. 5 years later, a new American reconstruction is carried out. It then allows a credible estimate of the length of the animal: 15.90 meters. Later, it will be estimated that the largest specimens could reach the 20 meters long.

It is this latest study which, by integrating the discovery of vertebrae, mainly questioned the kinship with the white shark. Indeed, the morphology of the Megalodon turns out to be more massive than that of its supposed parent. With a weight probably around 50 tons, the Megalodon would have looked more like a gigantic Carcharodon carcharias.

Undoubtedly, the Megalodon had an imposing and particularly powerful jaw. Its thick, sturdy teeth were probably capable of shattering the bones of its prey. Scientists believe that the Megalodon could prey on large prey such as whales, its jaw allowing it to pierce the rib cage of its victims and thus touch vital organs.

When did the Megalodon live?

The Megalodon lived from the Miocene to the mid-Pliocene, between 23 and 3.6 million years ago. This estimate is not unanimous among specialists, however, with some scientists fixing its extinction at only 1.6 million years.

Different hypotheses are put forward to explain its decline:

Mysterious marine environments

Creatures like the Megalodon fascinate with their incredible proportions when compared to the forms of life that we encounter today. The seabed still remains largely inaccessible to humans. Scientists regularly communicate their discoveries through general public reports, no doubt to fuel the curiosity of societies for these still very hostile places, and thus facilitate the financing of their expeditions. Their revelations often have a fantastic tone, as when it comes to showing giant squid, which is assumed to be up to 15 meters long. Also our imagination has something to panic: what other gigantic creatures that have not yet been observed could inhabit the ocean floor?

Photo credit: Luis Alvaz