Megalodon

WHAT SIZE WAS MEGALODON AND HOW MUCH DID IT WEIGH?

Megalodon (Carcharocles megalodon, "big tooth") is the largest predatory shark in the history of the Earth.  Several attempts were made to estimate the size of the prehistoric fish. In 1909, when the megalodon jaw was reconstructed for the first time, scientists estimated the length of the shark's body to reach 30 meters. Today's advances in vertebrate biology and new findings of megalodon remains helped to reduce the estimated size by half. Using different methods of studying the teeth of a predator, we get the estimated results of a body length from 13 to 18 meters. Only in 2015, after studying a large sample of teeth, an average length of 10 meters was obtained, and the maximum length of 15 meters. For comparison: a great white shark can theoretically reach seven meters in length. The size of megalodon is close to the largest marine reptiles of the Mesozoic era, such as mosasaurs and ichthyosaurs.

Why are shark teeth used in size estimation, and not parts of its skeleton? That is because sharks are cartilaginous fish. This means that their skeleton consists of cartilage and not of bones. Cartilage is poorly preserved. It decomposes before it turns to stone. That is why we have almost no megalodon remains, except for teeth. 

For a long time, the body mass of the megalodon remained the subject of controversy. It is difficult to draw conclusions about the body weight based only on the teeth of an animal. The lack of discovered remains of the giant predator prevented accurate estimates. If we reconstruct a megalodon based on the complexion of a white shark, we will get an estimated body weight from 41 to 47 tons. However, in order to draw conclusions about the body mass of extinct fish we can compare the dimensions of a megalodon and a whale shark. This method underestimates the weight to 30 tons. All the same, with such a body mass, the predator had to consume an enormous amount of food, more than a ton per day. During the study of whale fossils, the same age as megalodon, it became clear where the shark took such a large amount of food. Many skeletal remains of large marine mammals had characteristic injuries that fit the profile and size of megalodon teeth.

WHAT SIZE WERE THE TEETH OF MEGALODON AND WHAT IS THE SIZE OF THE LARGEST SPECIMENS FOUND?

Giant shark teeth are found all over the world. Their average size varies from 10 to 13 cm. Such dimensions are already impressive, since the teeth of a great white shark are only 7 cm long. However, several megalodon teeth with a length of more than 17 cm were discovered. The largest of the megalodon teeth found reached as much as 19 cm in its length.

In 1843, when megalodon was first identified, it was assigned to the genus Carcharadon, which also includes the white shark. Two huge sharks, with big jagged teeth — probably they are relatives. However, as time passed by science was developing completing the fossil record. Today’s taxonomy of sharks looks different from the one of a century and a half ago. The evolutionary paths of the white shark and the megalodon diverged more than 60 million years ago.

  Megalodon is considered to have the most powerful bite in the history of fish. His giant jaws could clench the victim with a monstrous force of 109 kN. This is three times stronger than the result of today's record holder — the crested crocodile. In terms of bite strength, megalodon is inferior to tyrannosaurus (more than 200 kN) and deinosuchus (more than 350 kN).

HOW MANY TEETH DID MEGALODON HAVE?

One should not forget that the megalodon's jaw was studded with a huge amount of sharp teeth. Predators like sharks tend to have a large number of teeth. The old ones are breaking down, wearing out, while the new ones are already on their way. The giant's two-meter jaw had more than 270 teeth arranged in five rows. Triangular notches on them, the same as those of a white shark, indicate a similar way of eating. The megalodon did not swallow its prey, nor does the white shark. Sharp and strong teeth with a length of more than 10 cm literally sawed off huge pieces of flesh of unlucky victims.

Certainly, speaking about megalodon, one cannot pass by its teeth as valuable items for collectors. The point is that shark teeth regularly fall out and are well preserved. Today megalodon is well studied, and there is no end to the findings. Small teeth do not cost a lot and can become an interesting and unusual gift, while the ones starting from 16 centimeters are already very expensive, and their cost can be as high as tens of thousands of dollars.

Nevertheless, size is not the only factor determining the cost. State of preservation and color affect it as well. The larger the size, the more difficult it is to find a well-preserved tooth. Large teeth in perfect condition are considered the most expensive and are usually classified into the category "museum quality".

WHAT DID A MEGALODON EAT?

The huge size of the shark and its monstrous teeth clearly hint at the place of a super predator in marine ecosystems. The Internet is littered with colorful pictures of megalodon tearing whales apart. Recently, there has been a reverse trend to "unmask" ancient predators, turning them into scavengers. It is not difficult to find videos made in an attempt to prove that the megalodon was a kind of scavenger that was slowly eating dead meat in the ocean. But what do paleontologists say about this?

Megalodon was an active predator that used different food strategies at different ages. Young megalodons hunted everything that moved, with their increasing size shifting to a diet of marine mammals. The main prey of adult megalodons were cetaceans 2.5 – 7 meters long, large fish and sea turtles. Prey with a length of more than 7 – 10 meters is less common in the megalodon diet. Still, like modern sharks, they were happy to have some carrion as well. 

During the hunt, the megalodon tried to attack from below. A ramming blow and bites aimed at the chest. The fins were often bitten off. Given the slowness of megalodon metabolism, adults were ambush predators. They could guard the victim for a long time in a deep water, and did not chase it if the victim managed to escape.

The feeding grounds of megalodons clearly coincide with the breeding grounds of cetaceans. Interestingly, white sharks that already inhabited the ocean at that time avoided megalodon habitats, preferring colder waters. This may indicate the high efficiency of the Big Mega as an active super-predator.

CAUSES OF EXTINCTION

The warm ocean and the huge abundance of food made the megalodon a very successful predator. The remains of an ancient shark were found in North America and South America, Europe, Africa, as well as Puerto Rico, Cuba, Jamaica, the Canary Islands, Australia, New Zealand, Japan, Malta, the Grenadines and India. However, what led megalodon to success also became his doom. The planet's climate began to change dramatically 2.6 million years ago, and the oceans were cooling down. Large fauna was destroyed, and the giant predator was simply left with nothing to eat. The influence of other top predators, such as killer whales is also one of the possible factors. Today, a white shark weighing 1-2 tons is a breakfast for young killer whales. However, most likely, the megalodon became extinct due to a complex of reasons that unluckily came down on it.