A new 3D model allows new insights into the body and lifestyle of the predator. It could eat prey up to 8 meters long in just a few bites – but at some point this was no longer an advantage.
An artist’s reconstruction of the megalodon shows how large it was compared to its prey, whales the size of modern-day killer whales.
The white shark, up to 7 meters long, has become the epitome of swimming horror, mainly through the film of the same name by Steven Spielberg. But there is one animal that would have swallowed him in a few bites: the megalodon.
A megalodon is up to 20 meters long and has a mouth that can open almost 2 meters. It should therefore be extremely reassuring for white sharks, other sea creatures and bathers that the basking shark Megalodon became extinct more than 2 million years ago.
An international team of researchers has now created a 3D model of this animal for the first time and published in the journal Science Advances. What it was able to deduce from this about the movement and feeding behavior of the megalodon is impressive.
The full scientific name of the prehistoric sea giant is Otodus megalodon. “Otodus” is Greek and describes the teeth of this genus as “ear-shaped”. “Megalodon” also refers to the teeth, it means “giant tooth”. The tusks, sometimes 15 centimeters long, are also the part of the body that is most commonly preserved as a fossil of this animal.
Because like modern sharks, the megalodon had a skeleton made of cartilage, not bone, and cartilage usually degrades before it can fossilize. Therefore, only a few parts of the spinal column of Megalodon individuals have been found so far. A reconstruction is therefore much more difficult than, for example, with a dinosaur, of which the entire skeleton has been preserved.
The megalodon weighed as much as ten elephants
But: “Sharks have been around for millions of years, and they still are today,” says Catalina Pimiento Hernandez, a professor at the Paleontological Institute of the University of Zurich, who helped design the study. “That’s why you have good modern comparisons that you can use as a guide.”
For their reconstruction, Pimiento and the other scientists used an exceptionally well-preserved fossil of 141 vertebrae found in Belgium and kept in Brussels. It belongs to a 46 year old individual.
The age is known because sharks have annual rings in their vertebrae, similar to trees. To model the skull and flesh, the research group used the great white shark as a model. It is closely related to the megalodon.
While earlier reconstructions of this special megalodon individual in Belgium assumed a length of almost 10 meters, Pimiento and her colleagues now come to 15.9 meters and a weight of 61,560 kilograms: That’s how much ten African elephants weigh. Megalodon is the largest shark that has ever lived.
The primeval shark was a fast swimmer
And that’s not all: the swimming speed calculated on the basis of body mass confirms earlier estimates: at up to 1.4 meters per second or 5 kilometers per hour, the megalodon swam faster than all creatures alive today, at least in everyday life, so to speak, when it is neither on the Jagd was still on the run.
One word that catches the eye in the scientific article is gape size. The paleontologists calculated them for two different angles. According to this, the basking shark opened its mouth about 1.2 meters wide at an angle of 35° and even 1.8 meters at an angle of 75°. These numbers indicate which animals the megalodon might have eaten. For example, the shark could swallow a 5 meter long whale in three bites. There was enough room in his stomach for a whole orca.
However, the megalodon may not use this opportunity every day. Bite marks on fossil whale bones show that Megalodon actually hunted them. And the megalodon’s estimated food requirement of almost 100,000 kilocalories per day sounds daunting.
But one ten-thousandth of a whale, or its ancestors living at the time, would have been enough for the megalodon to cover its calorie requirements. This is because whale blubber is extremely high in calories. And it means that once the basking shark had eaten such a large animal, it didn’t have to hunt for two months.
The scientists have presented their research and findings in a short film.
This of course begs the question: what does a basking shark at the top of the food chain do with all that free time? The same as today’s elite: travel. With the calories from one meal, the megalodon could swim more than 7,500 kilometers, for example from Europe to North America.
The great white shark is also known today to cover distances of 11,000 kilometers, so the scenario is entirely plausible. It is therefore not surprising that tooth fossils of the megalodon have been found all over the world: the scientists speak of a “cosmopolitan super predator”.
Lack of prey and competitive pressure lead to extinction
This predator was big, but apparently not too big too fail, one could say: it died out. For some time, the megalodon arguably occupied a niche with little competition with its ability to consume huge prey. But that suddenly changed. “The potential prey animals all live near the coast, the open sea is unproductive,” explains Pimiento. In an ice age phase 2.6 million years ago, however, huge amounts of water were bound in glaciers and ice. Sea levels dropped dramatically, coastal waters dried up and more than a third of large marine animals disappeared.
It might then no longer be of any use to the megalodon that it could devour a whale: “First it had to find it,” says the paleontologist. «In addition, new competitors appeared for the first time at this time. If large prey was no longer available, the megalodon would also have to eat smaller animals and suddenly had competition.”
In addition, many of the competitors could probably swim faster. “We can calculate the megalodon’s normal ‘walking speed’, but we don’t know how fast it was during the sudden ‘sprint’ that is crucial for hunting success,” says Pimiento. “But because it was so big, the water resistance was probably high.”
This put it at a disadvantage compared to its smaller, faster competitors. What came first, the competitive pressure, the lack of prey or the switch to smaller foods, is unclear and will probably remain so: “We may never know the exact mechanism or the chronological sequence of these events,” admits the scientist.
Size alone is not everything when it comes to survival. “Size and speed have to be in balance,” says Pimiento.
Ultimately, the megalodon is another example of an evolutionary attempt that did not catch on. The basking shark would still be worth an exciting film, possibly by Steven Spielberg.