Top Ten Sharks: #10 – Megalodon, Otodus megalodon

A man stood next to a reconstructed Megalodon jaw. As you can see it is…well…Impressive is putting it mildly, that’s like seeing the Grand Canyon and jumping into it – An unimaginable sense of awe followed by utter terror! (Credit: James St. John CC-BY-2.0)

Fuck it…Let’s get it out of the way.

It was always destined for the top ten, let’s be honest. It’s a pop-culture phenomenon, an ‘extinct-or-is-it?’ Horror-show and it’s all because of little more than teeth and jaws.

That’s about all we’ve ever found of Megalodon. No whole bodies, no well-preserved fossils. We’ve found some vertebrae too, they allow us to give a better approximation of its size, and there is, according to the Natural History Museum article about it, a jaw, brain-cavity, vertebrae fossil out there somewhere that’s not been properly seen.

So what is it about this barely known shark that has caught the public’s attention so much? Well the fact that of the jaws we do have two adult humans could probably stand upright, side-by-side in it and still not fill that gaping maw. How about that?

The name itself literally translates to ‘big tooth’ and, boy if that ain’t an understatement. The largest known, confirmed Megalodon tooth is approximately 20cm bottom to tip. Want some perspective on that? The Great White Shark – the largest predatory fish in the oceans today? Their teeth are usually around 7-8cm at their largest.

The black, preserved Megalodon tooth compared to two, fresh, Great White teeth. The size comparison is just stark, the differences in scale are incredible. (Credit: Parzi CC-BY-SA 3.0)

We’re talking about a literal sea-monster here. Using tooth data from other sharks and extrapolating an estimated size, we’re looking at 15-16m – around 50 feet for you old timers! The largest fish on earth today, the Whale Shark, only hits upward of 10m, and that thing does not have a jaw big enough to fit a trawler in and teeth like 7 inch razor-blades!

Why was it so big? It’s always chicken-and-egg with evolution so the answer is ‘because it could be’. At the time it existed the seas were warm and teeming with life, in all different shapes and sizes, maintaining stable ecosystems of giants.

This thing, Megalodon, was basically a whale hunter, though it probably ate other large fish, small fish, other sharks – let’s be honest, it’s a 15m predator with a mouth full of hundreds of knives, it can eat what the fuck it likes! If it walks into Gordon Ramsey’s restaurant and asks for a well-done filet mignon, Mr. Ramsey is not screaming about mistreatment of the meat and ejecting the heathen, he’s saying “Yes, sir, Mr. Shark, sir!” and overcooking some damn beef!

Much of the time Megalodon is presented as being like an over-sized Great White, which is a little misleading. Remember all that taxonomic classification nonsense we enjoy so much? Well, since we only know Megalodon by its teeth and jaws and little more, it has been bumped around a bunch of different genera (remember those? one step up from a species) and families (one step up from a genus). It used to be put in with the Lamnidae – the white sharks, of which the Great White is a member, but is now considered a member of the family, indeed potentially the last of its family, the Otodontidae. They’re closely related to White Sharks but diverged sometime around the Early Cretaceous (around 145-100 million years ago).

As a result while we have size ranges and all the evidence it was a hulking sea-monster, what it actually looked like is still up for debate. Sharks don’t differ too much in their basic appearance but that’s like saying all humans look alike! Yeah, most have two arms, two legs, two eyes, nose, mouth  – but the configurations vary greatly. Well the same is true of shark species. The basic body-form we can estimate, the exact specifications are tough. But what do you really need? It’s a BIG FUCKING SHARK! If your imagination can’t work magic and inspire awe with that you’re broken.

A demonstration of the scale of the beast we are talking about here (although referred to by its old classification as Carcharodon megalodon, not Otodus megalodon) – The grey shape is the largest possible size, the red shape is a conservative estimate, the purple shape is the average size of a modern whale shark (the current largest fish in the world) and the green shape is the average size of a modern great white (the current largest predatory fish in the world). You wouldn’t want to go swimming with the red shape. (Credit: Popoto, Misslelauncherexpert, Matt Martyniuk, CC-BY-SA 4.0)

On the subject of awe let’s get to the investigations and estimations of jaw strength. A pretty astounding paper based upon modelling suggests that the largest living predatory fish, the great white shark could exert a force of between 10,000-18,000 Newtons.

What does that mean? Well a ‘Newton’ as a measurement is the amount of force needed to accelerate one kilogram of mass at the rate of one meter per second squared in the direction of the applied force – In this case, squeezing it between jaws.

For the sake of comparison a Newton in force is roughly equivalent to around 100g in weight, which means the bite force of a Great White Shark is like having around 1,500-2,000kg on top of you – Unless I’ve got my maths wrong, it’s not my strong suit.

So Megalodon is like, what? Just over twice the length of a Great White, just over twice the tooth length? We’re looking at doubling the force, right?

Nuh-uh! Using the same modelling technique for known Megalodon jaws the team behind this experiment determined the force was somewhere between 100,000-190,000 Newtons. TEN TIMES THE GREAT WHITE.

That is a biting force equivalent to around 15,000-20,000kg on top of you.

But consider this, those numbers of kilograms are, obviously a useless simplification because the bite force is not distributed equally over the whole jaw. That Newton-to-Mass estimate is if it was a heavy, flat weight squashing you, but we’re talking jaws full of blades squeezing you with pressure here! A human is like a slice of juicy ham to these things. You’d be tender, bones and all!

If this modelling is accurate and those numbers are anything remotely like correct we’re possibly looking at the most powerful bite ever known on planet earth.

A highly hypothetical artist’s impression of Megalodon chasing whales. As mentioned, since all we have to go on is a few teeth, jaws and vertebrae the actual appearance of Megalodon is much debated (Credit: Karen Carr and the Virginia Museum of Natural History CC-BY-3.0)

But have you ever seen a shark take a bite? They don’t just monch down, a lot of predatory sharks either employ a side-on bite movement or literally shake their heads. This thing…It could probably shred a boat! I mean it was adapted to eat whales and there’s evidence of the whales fighting back (with Megalodon tooth fragments found in preserved whale ribs, for example) so we’re talking a 10-15m oceanic super-predator that would have had to try and shred a whale in one to avoid damage!

The evidence we have, tooth marks on preserved whale bones, tooth fragments in whale ribs, seem to make this the preferred method of hunting for Megalodon. It did not, like modern great whites, attack the underbelly of its prey, or their exposed part. All evidence seems to suggest it literally bit down on the chest and tried to crush and slice right through to the heart and lungs.

But Megalodon lived a long time, and it’s hunting strategies seem to have been different for larger whales that adapted, including taking bites out of fins and tails to immobilise their prey first.

This thing was smart.  

It’s incredible, it really is. The truth is better than all of the myths and modern bullshit movies.

They weren’t alone, either, though an apex predator that seems to show a population distribution all around the world you’d think Megalodon would have ruled the seas but they were also full of giant predatory whales, like Livyatan melvillei, estimates put it at a 14-18m beast named after a literal biblical monster. With an upper and lower jaw chock-full of giant teeth, Megalodon and Livyatan were probably competing for a lot of the same prey in a lot of the same waters.

A skull of Livyatan melvillei – the name a reference to both the ‘Leviathan’, a monster of biblical origin, and Herman Melville, author of the book Moby Dick. Taken at Museo di Storia Naturale di Calci – Pisa. You can tell by the teeth this is a predatory whale, related to modern day sperm whales. This monster, and Megalodon, were likely competing for a lot of similar prey, other small whales and sharks. (Credit: Ghedoghedo CC-BY-SA 4.0)

That, though, is not likely why they went extinct. While we cannot say for definite why Megalodon disappeared it seems to fall off the fossil record around 3.6 million years ago, and we have a good enough understand of many reasons why.

Between the Oligocene (around 35-25 million years ago) and the Pliocene (around 5-2 million years ago) there were drastic climatic changes. Glaciation, creation of massive seas of ice at the poles, lowered ocean water levels and their temperatures dropped too.

Because of the glaciation and lowering sea levels, a lot of the shallow-water nurseries these baby giants would have had to grow up in turned to dry land. The decreasing temperatures of the water reduced the range of Megalodon significantly. Possibly most importantly, since Megalodon had so successfully competed in its niche a lot of other larger shark species were already better adapted to slightly cooler water for having to avoid this voracious predator and many of their whale prey species adapted likewise.

Effectively its nurseries were drained, its territory shrunk and it had nothing left to eat.

So we get to the biggest question, one provoked by cryptozoological speculation and the Discovery Channel’s placement of ratings over scientific rigour. Is Megalodon still out there somewhere?

From everything we know about it, unlikely.

A standee for the movie ‘The Meg’ – An example of the use of Megalodon as a ‘monster’ in public consciousness. By this point the Megalodon is probably as famous as Godzilla! (Credit: Brecht Bug CC-BY-NC ND 2.0)

It was a massive, unmistakable super-predator. Mean length of most specimens worldwide is around 10m (or 32 feet) it lived in warm waters, left its young in tropical, shallow-water nurseries and ate fucking whales, for crying out loud!

There’s a lot of mysteries in those seas and oceans, I have no doubt there are undiscovered giants waiting to be found or re-found after presumed extinction. Every indication would suggest Megalodon is not one of them. We would expect to see its baby form swimming around shallow reefs, competing with modern day reef sharks, we would expect to find half-eaten whale carcasses, and more importantly, yeah the sea is big but this thing is a 10-15m hunger-tube! People go out looking for sharks, in warm waters, they chum the area, they drag carcasses behind their boats – Someone would have seen something!

A reconstruction of a Megalodon from  “Museo de la Evolucion”, Puebla, Mexico. Again, debate rages as to the likely appearance of the Megalodon, here they seem to have used the white shark as their basis for the fundamental shape and proportions. This example is built at 16m in length. A truly impressive creature. (Credit: Sergiodlarosa CC-BY-SA 4.0)

I hate to burst the bubble, but Megalodon is extinct. There are no more in our waters. But count your blessings. This is almost literally the first article about natural history or wildlife where I can honestly say the decline or extinction of a species is not partially or exclusively the fault of humans!

At the same time, the legend will never die! Humans seem fascinated by predators and the larger and more awe-inspiring the better. In that sense, Megalodon is likely the largest predatory fish that ever existed, with a set of jaws that could swallow a train whole, and teeth and a bite that could tear through a tank.

That’s going to stay with us, haunting us, fuelling our fears of the unknowns of the ocean.

Want to dive deeper into some aquatic shark content?
Our Introduction will give you the basics of shark biology, ecology and natural history.

#9 – The beautiful and quick blue shark
#8 – Known for it’s spiral of jagged teeth, Helicoprion – the Buzzsaw shark!
#7 – The frilled shark, a mysterious living fossil with much to tell us about sharks past.
#6 – The Great White, Apex predator, whale scavenger, more intelligent than we thought.
#5 – The Megamouth Shark – One that tells us more about what we don’t know!
#4 – The Graceful Hammerhead family – Much overfished, and is one a veggie?
#3 – The aparently philosophical basking shark! – Happy just existing.
#2 – The longest living vetebrate on earth – The Greenland Shark

Published by Karl Anthony Mercer

An overly curious lovechild of Grumpy of the Seven Dwarfs and the kitsch pen section of Paperchase. Karl is on a mission to expose the seedy underbelly of academia, and thus making it appealing to wrong 'uns.

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