Can you imagine what Earth was like 20 million years ago? And the ocean? Here's a fact: 20 million years ago, the largest predatory fish that ever existed lived in the ocean: the Megalodon. The Megalodon (Otodus megalodon) was a giant shark with similar shapes and habits to the current white shark (Carcharodon carcharias).
The word “Megalodon” comes from the Greek and means “big tooth”. Being such a powerful animal, it is interesting to ask ourselves Why did the Megalodon become extinct? In this article on our site, we tell you this and other curiosities about the Megalodon shark.
Megalodon's teeth
An interesting fact about sharks is that they have rows of teeth in their jaws, and while the oldest teeth fall forward, the back ones grow and occupy the most frontal places. During its lifetime, a shark can change between 20 and 30 thousand teeth On the other hand, sharks are cartilaginous fish; this means that its skeleton is made up of cartilage and not bone.
These two pieces of information are important to understand the following: the reconstruction of the Megalodon has been done only from its teeth!
Megalodon has been extinct for millions of years, and the only way to find out about it is through the fossil record. It is very difficult for cartilage to fossilize, however, shark teeth do fossilize very easily. Fossils of Megalodon teeth have been found since the Renaissance, but it wasn't until 1667 that they were discovered for what they really were.
The fossil record of Megalodon currently has teeth, some central vertebrae and coprolites (fossilized feces); Based on these data, it is now known what the Megalodon was like, what habits it had and why it became extinct.
The fossilized teeth of Megalodon can measure up to 18 cm long and 17 cm wide The total number of teeth present in the jaw of a Megalodon was about 250 and they were distributed in 5 rows. Estimates of Megalodon characteristics are based on the fossil record and are made from models based on the extant great white shark.
Isn't it amazing how much you can tell from just an animal's teeth? The job of paleontologists is to recreate the life of the past from the clues of other times that are preserved until the present. Do you want to know how much information they have been able to obtain about the Megalodon from the fossil record? Read on and find out!
The Megalodon shark and its characteristics
The Megalodon shark belongs to the Lamniformes order, which is made up of the best-known shark species (such as the white shark), and within this order it belongs to the Otodontidae family, which today is found completely extinct.
What was the Megalodon like?
Megalodon teeth have a series of pores along the root surface, where the circulatory system entered to supply nutrients while the tooth was forming. This indicates that the nutritional system of this animal was very complex, which is consistent with a shark with high nutritional demands that used and replaced its teeth with high frequency.
From this, it is intuited that it was a large and aggressive shark, that fed on large prey, and that it had a high metabolic rate. Current models, made from comparisons with the current white shark, indicate that the Megalodon was a very fast shark, being able to swim at about 55km/h This is much faster than current white sharks, which swim up to a speed of 35km/h.
Megalodon feeding
Many fossilized vertebrae of various animals have been found marked by bites from Megalodon teeth. This evidence helped to determine their diet, which possibly consisted of a wide repertoire of prey, such as cetaceans of various sizes, as well as seals, sirenians, sea turtles and fish. However, due to its large size, it is believed that it primarily targeted larger prey, such as whales
Whale bone fossils have been found with markings that perfectly match possible bites from Megalodon teeth; mainly those of a group of whales called the Cetoteridae (now almost all extinct except the pygmy right whale), in which he specialized.
When did the Megalodon live?
Otodus megalodon first arose 25 million years ago and became extinct 2 million years ago. That is, it existed for 20 million years, from the beginning of the Miocene to the end of the Pliocene, in the Cenozoic era.
Contrary to what many people believe, was not contemporary with the dinosaurs, but arose long after their extinction (which was more than 60 million years ago).
Megalodon teeth have been found on all continents, and it is believed that they inhabited subtropical, temperate latitudes and mainly in relatively warm waters. cold. Because of their size, adults could not live in the warmer, shallower coastal areas.
However, juveniles did live in shallow tropical waters. In these habitats, they could get enough prey, but it is also believed that Megalodons were cannibals and preyed on juveniles, so it was convenient for them to segregate geographically.
How big is a Megalodon?
The shape and size of the Megalodon have been reconstructed from its teeth and using the modern white shark as a model. Early models suggested that the Megalodon could reach 24 meters in length However, they had made a mistake. They had been based on the size of a reconstructed jaw, made up entirely of the largest teeth found.
Later, they realized that the Megalodon had teeth of various sizes. In any case, the mandible reconstructed under this consideration is no less than two meters in diameter (with the mouth open).
How much does a Megalodon weigh?
Today, it is considered that the average length of the Megalodon was between 15 and 18 meters and that its approximate weight was 50 tons.
As points of comparison, keep in mind that current white sharks measure around 4 or 6 meters, whale sharks 12.5 meters and the blue whale 25 meters.
When did the Megalodon become extinct?
Although there are some cases of people who claim to have seen a Megalodon today, and others who speculate that it could continue to exist in the depths of the ocean, there is scientific consensus regarding the extinction of the Megalodon.
Megalodon teeth have been recorded in Mexico dating from 11 thousand years ago, but these are not taken seriously by the scientific community. The most recent accurately dated fossil record for Megalodon is from the late Pliocene, recently over 2 million years old
You may also be interested in this other article on Prehistoric Marine Animals.
Why did the Megalodons become extinct?
Although the Megalodon was the largest predator of its time, it had some serious competitors. During the last two million years of their existence, Megalodons coexisted with modern white sharks Megalodons as adults were much larger than white sharks, but these were they may have been a competition for the young Megalodons, with which they shared the same size range.
However, the greater competition that the Megalodons experienced was not due to a question of size, but rather to a question of organization. The killer whales were evolving; They are very intelligent and organized animals that work as a team and catch large schools of fish. In addition to these animals, they could also hunt the young Megalodons, which are also about the same size as killer whales (they are known to hunt great white sharks).
Other whales noted for their great feeding abilities that existed at that time were the humpback whales. The humpback whales fish in groups; they dive under the fish and they all exhale at the same time enclosing them in a column of bubbles. They come to the surface in a group with their mouths open and eat the entire school of fish.
In Megalodon's prime, there were many whales belonging to many species. In the beginning, the food was plentiful and the competition was not so great. However, 2 to 3 million years ago, there were c changes in the worldwide current system, causing upwelling to decrease. Upwellings bring nutrient-rich waters to the surface, thus feeding the entire food chain. Due to decreased upwelling, the amount of food available decreased and competition became more intense. The diversity of whales decreased and the Megalodon, which due to its size had a great demand for food, failed to survive.
The cooling of the atmosphere also hurt Megalodon. Glaciers emerged that lowered sea level, increased salinity and lowered temperature.
Now that you know why the Megalodon became extinct, you may be interested in this other article on The world's largest sea fish.
