Why the Megalodon is gone for good.

Odotus megalodon was a massive, ancient shark, with the largest specimens found to be just under 60 feet in length at about 17.9 meters. To put that into perspective, the largest (reliably measured) Great White Shark ever caught was just around 6.0 meters in length, or about 19.7 feet. The sheer size of this ancient creature is enough to simply propose (much to the dismay of many shark-lovers such as myself), that if this creature were alive today, we would have simply found it already. But, I digress, let’s jump into the details to really explain why the ancient Megalodon cannot exist in the oceans today.

The Mariana Trench Theory

Perhaps one of the most popular theories I have heard in this debate is that the Megalodon would live in the Mariana Trench. There are several issues with this theory, but I’ll start with the most obvious.

Food

For a shark as large in stature as the Megalodon, there is not possibly enough food in the Mariana Trench to sustain one shark, let alone a reputable population. On average, a Great White Shark consumes about 0.5 to 3 percent of its body weight each time it hunts once every few days. This may not seem like much, but you have to remember that sharks are much much bigger than us. And this Megalodon was 3 times the size of a Great White on average. This means that the Megalodon would have to hunt and consume a massive amount of the xenophyophores, amphipods, and small sea cucumbers that live in the depths, not one of which were a part of the creature’s diet or hunting lifestyle. It is simply not possible to see a sustainable and thriving colony of sharks living in a near ecological dead zone of their diet.

Pressure

The Megalodon is related to the order of sharks known as the Lamniformes. This order includes species such as the Great White, Thresher, and Mako sharks. The Great White, Megalodon’s closest relative, lives about as deep as 200m in the ocean. The Mariana Trench Theory would suggest that the Megalodon would be living 11,034m under the surface. The pressure that deep in the ocean is about 16,000psi, easily enough to destroy any submarine that attempts venture down there. With a cartilage skeleton, the shark’s body would simply collapse under than kind of pressure.

The Cold of the Depths

The average temperature in the Mariana Trench is about 34-39 degrees Fahrenheit, or about 1-4 degrees Celsius. Moderns Lamniformes thrive in temperatures of 54-75 degrees Fahrenheit, or 12-24 degrees Celsius. Now, studies have shown that the Megalodon thrived in slightly colder waters, and might have struggled due to the rising temperatures of climate change. However, they primarily lived in the cold during development, and returned to more coastal areas later in life. We loop once again to our point that Megalodon, if it were alive, would have been found already.

Undiscovered Descendant?

Let’s close off this essay on a good note. While it is highly unlikely we will ever find any trace of the Megalodon in the deep, we can still observe and appreciate what this creature was like in its time by observing its relatives. The modern Lamniformes of our time give us insight into how their Cretaceous ancestors lived, hunted, and bred, and their existence allows us to appreciate what many years of evolution have done to create these apex predators. Perhaps there is an undiscovered, more distant ancestor of the Megalodon thriving in the deep waters of the undiscovered sea, but even with that thought, we would still only have a piece of what it would be like to live with the great, ancient sharks of our planet’s past.