Megalodon Facts

Megalodon Profile

The largest shark ever to have lived may have shared its world with some of the earliest human ancestors.

Some say it’s still alive today, hiding in the cold depths of the unexplored oceans. They’re wrong, but it’s still fun to think about. This is the Megalodon.

Megalodon Facts Overview

Odotus megalodon has yet to give up many of its secrets. As with most sharks, they didn’t fossilise well on account of their lack of calcified bones. What we do know comes from their teeth, a couple of possible vertebrae, and a whole lot of guesswork.

Still, something is fascinating about a real-life ocean monster, bigger than a bus, and with a penchant for flesh.

Interesting Megalodon Facts

1. We don’t know what it looked like

Despite what Spielberg might tell you, there’s a lot less to infer from fossils than you might think. Some dinosaur or mammoth depictions, for example, are extrapolations from a single bone that fell out of a cliff in Dover.

That said, there is a lot a talented palaeontologist can gather from a single bone. Some laws of biology apply almost universally, so the right femur, or lower jaw, or even a particular tooth, can shed light on what the rest of the animal might have looked at.

With Odotus megalodon, an animal that was primarily made out of cartilage, that tooth is basically all we’ve got. Hence the name, megalo: great, -odont: tooth

So, much of what can be done here is guesswork based on various tiny details on the tooth. However, teeth are one of the best pieces of an animal to look at when you want to know about it.

First of all, the tooth resembles that of a great white’s, which is what led people to originally assume the megalodon was an ancestor of the iconic shark from Jaws. The triangular, serrated teeth do suggest it fed on mammal flesh, rather than fish, as do the fossilised grooves in the bones of giant whales and dolphins.

But recent research has suggested it was a different lineage to the great white. It’s now thought The Meg was a relative of the mako shark.

2. We don’t know how big it was

The size of the tooth does give a clue to the size of the jaw that housed it, and the largest megalodon teeth are around 17 cm (7 inches) long. That’s significantly larger than the great white and has led to some frightening reconstructions of the jaw that can fit ten human beings inside of it.

Mathematical models and a lot of speculation have sent estimates back and forth between different groups, with one relatively persuasive calculation returning a 16m (52ft) shark with a 3.8-meter (12.4 ft) dorsal fin and a 4.7m (15 ft) head. ¹

3. So, what do we know?

The trouble with reporting sciences is that unless you read a statistical analysis there’s no mention of the margin of error.

Essentially, nobody tells you how likely they are that they’re right. That’s why, when people report on something as speculative as megalodon physiology, they seem to say it with the same confidence they’d talk about gravity or evolution. This can be misleading when there isn’t nearly the same overwhelming consensus behind what they’re implying.

Still, inferences can be made with some certainty. The teeth suggest a robust and meaty prey item.

This means powerful jaws and a large, muscular neck. These muscles might give the animal a bit of a curved snout.

The size also tells us that this animal would need a lot of food with high caloric value, suggesting a robust body. The trouble is, around this point is where things start to get a bit iffy.

There are hundreds of species of shark alive today, displaying a diverse range of physiologies, not to mention all of those weird lineages that went extinct like the spiral-jawed shark Helicoprion, whose jaw, until recently, was mistakenly thought to sit outside of its face.

The point is, guesses are often not very imaginative. Sometimes, they’re too imaginative. Other times it’s a mixture of both. And each guess that’s based on a previous guess suffers from compounding inaccuracies.

One thing we do know is that they’re extinct. Despite what the Discovery Channel might try and tell you. ²

4. They coexisted with hominins

Megalodon teeth wash up on the shores all the time. Yet, these are fossilised teeth, not fresh ones, and this should go some way to proving that they’re long dead. Still, some of these fossils are frighteningly recent.

The most reliable guess at The Meg’s extinction puts it at around 3.5 million years ago, well into the period of some of the early bipedal hominids, and ancestors of modern humans. Could their paths ever have crossed? Could one of these sharks ever have gulped down an early human, carried out to sea by a tropical cyclone or tsunami?

Could we all have descended from someone whose untimely demise came at the teeth of the largest shark ever known? ³

5. 3.5 million-year-old poop rocks

Of what we do know, that which we can’t get from the teeth might come from the product of those teeth. Shark coprolite, or fossilised poo, can shed light on some of the more unusual elements of the megalodon’s physiology.

It’s thought that megalodon poop was an impressive 14cm log that was spiral in shape, suggesting the same is true about the lower part of the shark’s intestine or spiral valve.

It’s clear that the droppings were from a meat eater, as the bone content is what allows them to survive the fossilisation process, but exactly how these poop rocks can be identified to the species level is unclear.

It’s suggested that they were found in a deposit surrounded by hundreds of megalodon teeth, but you’d expect any animal to defecate in that situation. ⁴

6. They were likely the largest fish to ever live

Given the size of their teeth, it’s safe to say that these sharks were enormous. In fact, it’s believed that they were the largest fish ever to have lived. You might be thinking that toothless sharks, such as whale sharks or basking sharks would leave no trace in the fossil record, and so could have been bigger and nobody would ever know.

But as it happens, toothless sharks do have teeth and do turn up in the fossil record. At least, the ones we know about do. Both whale sharks and basking sharks have tiny teeth that survive in the fossil record and can be traced back for hundreds of millions of years.

One possible contender for the accolade is an extinct bony fish called Leedsichthys.

Again, this is all extrapolated from a very limited fossil collection, but with the recent reduction in Meg size, and the “not unreasonable” suggestion that this fish could have hit 16 meters, they were likely around the same size.

Still, even as the largest fish, they were beaten by a mammal.

7. Megalodon wasn’t the largest predator

It didn’t even have the largest teeth! A gargantuan whale likely competed for resources with the megalodon.

The predatory sperm whale Leviathan may have even crossed paths with the shark, and it’s thought that an increase in competition from large may have contributed to the extinction of the megalodon, as the climate changed and waters grew colder.
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Megalodon Fact-File Summary

Scientific Classification

1. Kenshu Shimada (2021), “The size of the megatooth shark, Otodus megalodon (Lamniformes: Otodontidae), revisited“, An International Journal of Paleobiology.
2. Becky Crew (2013), “Prehistoric ghost shark Helicoprion’s spiral-toothed jaw explained“, Scientific American.
3. Riley Black (2007), “Laetoli at ~3.5 mya“, National Geographic.
4. Adrian P. Hunt, Jesper Milàn, Spencer G. Lucas, Justin A. Spielmann (2012), “Vertebrate Coprolites“, New Mexico Museum of Natural History & Science.
5. Nicholas St. Fleur (2016), “Foot-Long Ancient Tooth Discovered on Australian Beach“, The New York Times.