MMXXVI VOL21 No.893

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Megalodon

The largest sharks that ever existed. What is known about them and why they became extinct. Can they still exist?
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Megalodon

Megalodons, one of the most amazing predators that have ever lived in the seas… and we know nothing about them. Except what marine paleontologists have imagined by analyzing their teeth, without being able to agree with each other.

This article explains why no fossilized megalodons have been found. Their actual size. When they inhabited the oceans. Their predators, the main theories about their extinction and the great unknown; is it possible that they still exist hidden at the bottom of the seas?

10 The only megalodon remains that have been found are teeth

The reason why not much is known for certain about megalodons is that only teeth of this species have been found scattered on the bottom of the oceans, along with a few fossilized vertebrae.

The teeth are similar to those of modern sharks, although much larger, about the size of an adult male palm of the hand and even larger.

Megalodon
Mmgalodon tooth and reconstruction of a jaw at the Smithsonian Museum, Washington DC. The jaw is as large as the entrance door to the museum. Teeth appear abundantly on the seafloor, suggesting that megalodons were a very common and widespread species.

For this reason, it is assumed that megalodons were relatives of sharks and, as sharks, did not have a skeleton. Only soft fibers and cartilage. Once the animal died, these fibers disappeared, consumed by scavengers or by decomposition.

9 The size of a megalodon

Extrapolating from the remains found, it is estimated that the megalodons could reach a maximum size of 20.3 meters (67ft) long, weighing 103 tons. In other words, a shark the size of a modern bus, the largest shark that has ever existed.

The open mouth had a diameter of about 3 meters (10ft), enough to swallow a human being without even chewing.

The teeth were designed to break bones, exerting a force of up to 182200 newtons when closing their jaws. Comparatively, human hands can squeeze up to 300 newtons. A crocodile has a bite of 16000 newtons.

Megalodon
The size of megalodons compared to a great white shark (carcharodon carcharias), humans and livyatans. Livyatan whales lived at the same time as megalodons and were their main predators.

With such a size, an adult megalodon would need to ingest 1200kg (3,300lbs) of food per day. The teeth suggest that they were carnivores. The high caloric needs suggest that they favored large prey such as giant squid, large marine mammals, baleen whales, seals or sharks smaller than themselves. A human being would not even have served as an appetizer.

The largest whale species that has ever existed and the largest known living being is the blue whale. It reaches a length of 30 meters (100ft), weighs 199 tons and feeds on krill (small shrimp) at a rate of 3600kg (8,000lbs) per day. They appeared 1.5 million years ago and are so massive that a megalodon could not sink its teeth into them.

8 It is not known what they looked like

The megalodons are usually represented as if they were giant white sharks. The truth is that it is not known what shape they had, nor what colors their skins were.

Megalodon
Megalodons are depicted as if they were larger great white sharks. In the image, a megalodon eating a great white.

Like today’s sharks, they could have had hammerheads, giant saw-shaped snouts, or long snout, as in the case of goblin sharks, living fossils with a 125-million-year-old lineage.

7 Inhabited 23 – 3.6 million years ago

Megalodons emerged 23 million years ago, in an era called Early Miocene. Dinosaurs had become extinct much earlier, 65 million years ago, so they had no competition from them.

Its habitat extended throughout the oceans, in waters deep enough for such a large species, especially the tropical areas where most teeth appear.

Megalodon
Megalodon hunting a poor whale.

Dental remains have been found at latitudes up to 55º north, off Canada, the North Sea between the Danish, German and Finnish coasts or south of the Alaskan coast.

6 Megalodons were not the kings of the sea

Even as the largest sharks ever, megalodons were not the top predators in the marine food chain.

They coexisted with other large animal species capable of attacking megalodons such as ancestral killer whales and five species of macroraptorial sperm whales, especially the livyatan or liviatan.

Megalodon
A livyatan splitting a megalodon in half.

Libyatan whales, of which partial remains of jaws have been found, with a length of about 17.5 meters (57,5ft), were not as large as megalodons. They had larger teeth though, up to 30cm (12 inch) long and pointed, capable of splitting the large shark in half.

5 Why did the megalodons become extinct?

The quickest answer is that it is not known. 19 million years ago, 90% of the sharks that populated the seas became extinct, without the exact reasons being known, since there were neither climatic changes nor sudden cataclysms.

Megalodon
Jason Statham playing with a megalodon in the film “The meg (2018)”. If the megalodons hadn’t gone extinct, our favorite bald guy would have killed them all.

The megalodons survived this purge but not the extinction of the marine megafauna between 3.5 and 2 million years ago. It is believed that megalodons disappeared at the beginning of this period, 3.6-3.5 million years ago. An extinction about which there are theories without the slightest scientific consensus.

4 Extinctive theory 1; climate change

One of the most widely accepted theories is that the beginning of the extinction of the marine megafauna coincided with the beginning of a period of global cooling that led to the Quaternary glaciation, 2.58 million years ago.

Megalodon
The big fish eats the little fish.

The cooling of the sea would not directly affect the megalodons, since they inhabited northern areas of cold waters, up to the 55th parallel north. The cooling rather disrupted their entire food chain.

3 Extinctive theory 2; lack of prey

This is a theory with unexpected twists. Global cooling affected the diversity of megalodon prey. Marine megafauna disappeared, along with 43% of turtles and 35% of seabirds. The problem is that megalodons became extinct very early in this period.

Megalodon
Humans would not even serve as an appetizer for a megalodon.

One possibility is that the giant sharks’ voracity eventually killed their favorite prey. Then they were unable to ingest the necessary calories by capturing smaller animals, in sufficient quantity to maintain their basal metabolism.

Another option is that megalodon prey were selectively adapted, being able to swim faster than their hunter.

2 Extinctive theory 3; exterminated by their predators

Predators do not usually hunt each other. Nevertheless, in the face of a decline in prey, it is possible that great whales such as liviatans would have to resort to hunting megalodons, eventually extinguishing them .

Any other extinction theory is possible. The slightest change in the ecosystem can unleash a chain disaster.

Megalodon
Livyatan vs megalodon.

An alteration in marine salinity, could wipe out those species that cannot tolerate the change. Counter-intuitively, it is believed that the oceans have been losing salinity over time since their creation.

Water can be contaminated by natural causes such as underwater earthquakes or massive algae blooms, which release toxins affecting the entire food chain.

1 Could there be any megalodon left alive?

Accepted science denies such a possibility because there is no scientific evidence to support such a claim. There have been no sightings, which should take place for such a large animal. Its original habitat no longer exists. There is not enough prey in the sea to feed it.

However, the deep sea continues to hold mysteries that give rise to the belief that megalodons may still exist. From time to time remains of great white sharks appear floating, with bites from animals even larger than them.

Megalodon
Image broadcast in a National Geographic documentary, in which it was defended that megalodons could still exist. The photograph shows two German u-boats skirting Cape Town, South Africa, in December 1942. The shark in the background would have a length of 20 meters (66ft) between dorsal fin and tail. With this size it would be in fact a megalodon. The image raised controversy as it was endorsed by an institution such as National Geographic. Eventually, it was proven to be a hoax.

The next story is true. A team of Australian marine biologists tagged a great white shark with an electronic tracking device. Four months later, the signal became too static, they went out to sea and located the tracker floating in the water.

When analyzing the data collected in the device, they found a sudden rise in temperature and a rapid drop in depth to 600 meters (1,970ft).

The most logical explanation is that “something” had eaten the shark along with the device. The digestion had caused the temperature rise in the sensors and then the attacker had submerged to 600m (1,970ft).

Megalodon
More from the film “The meg (2018)”.

Well, great white sharks have no natural predators except for humans and, on rare occasions, killer whales. These whales usually descend to depths of 100 meters (330ft), with an experimentally recorded maximum of 259 meters (850ft). They cannot reach 600m (1,970ft).

There are only three other animals capable of annihilating a great white shark – not including Jason Statham. Sperm whales could eat one and go down to 600 meters (1,970ft) but it has never been scientifically proven. Their favorite prey among the sharks are the wide-mouthed sharks, a 5.5-meter (18ft), toothless species that feeds on plankton.

Giant squid or colossal squid are capable of killing a great white shark, only they would leave circular marks on their remains.

The last option is another toothed shark larger than the great whites and the only known species is the extinct megalodon.

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