After over a year of hard work, I’ve finally completed my Megalodon documentary!!! You can watch it on YouTube and go on a journey back in time!
Here’s the script:
Otodus chubutensis. Twice the size of a great white shark, this megashark hunted whales and other huge prey in Miocene seas. But, in these ancient waters, there’s always a bigger fish, and no fish can compete with Megalodon, the largest predatory fish that ever lived.
30 miles off Wilmington, North Carolina, Megalodon lies dormant in the depths of the North Atlantic. The rough waters off North Carolina are unforgiving and have claimed countless lives. Slapping on scuba gear, I dive into the sea to awaken this megashark from its long slumber.
Out here, the water is deep, averaging 25 to 30 meters (80 to 100 feet), so diving here requires advanced skills and training. But it’s not all bad. These waters are often very clear. This area of ocean is bathed in the warm Gulf Stream current, which makes visibility much more pleasant for divers and marine life alike.
Soon, I find a Megalodon tooth lying on the seabed. These teeth have been in the ocean for millions of years, and I’m the first person to touch them. I can only imagine how long they’ve been down here. On all three of my dives, my catch bag is full of huge teeth.
When I recover fossils, I like to imagine how they reached their final resting place. Fossils are just pretty rocks. I can’t deny that. But they’re pretty rocks that tell us stories that transcend eons.
When we find a fossil, we’re finding a sentence in Earth’s 4.6 billion year book. The stories are messy and incomplete, but they’re no less beautiful.
Cracking open this book to the Megalodon chapter, we find a story that spans 19.4 million years, from the Miocene to the Pliocene. Over this time period, Megalodon left behind millions if not billions of teeth. Each one writing a sentence, each one telling a story.
Megalodon’s name revolves around it huge teeth. In Greek, megalo means “big” and donti means “tooth”.
Since I recovered these teeth from the seafloor, they are caked in coral and limestone deposits that have accumulated over millions of years. To expose the teeth, these calcified layers need to be removed.
Using a vinegar and water solution, I add the teeth to a basin and soak them for a few hours. This loosens up the calcium deposits and allows me to start exposing the fossils. I’ll often use another tooth to scrape the loosened limestone off the teeth, but if I can use a toothbrush or other gentle instrument, I will.
Soon, the teeth are restored, and I soak them in water to remove any remaining vinegar to prevent damage.
But, while the “big tooth” shark was the largest of the megasharks, it was not the only giant shark to exist. Megalodon came from a long line of sharks that can be traced back to teeny tiny Cretalamna, which lived alongside the dinosaurs in the Cretaceous Period.
Megalodon’s rise is associated with the dinosaurs’ fall. The disappearance of marine reptiles from the world’s seas left biomes vacant for sharks.
This vacancy allowed a huge shark species, known as Otodus obliquus, to dominate the early Cenozoic seas. Otodus obliquus was very large, growing between 30 and 40 feet (9.1 to 12.2 meters) and was an apex predator in its era.
Over time, Otodus species would grow even bigger, and their teeth would broaden and develop serrations. These adaptations allowed these megasharks to pursue increasingly larger prey, including marine mammals.
Some species, like Otodus chubutensis, have teeth that are almost indistinguishable from Megalodon. The main difference between Megalodon and chubutensis teeth is the cusps, which are mostly absent in Megalodon teeth.
Otodus chubutensis was in the same size class as Otodus obliquus, growing between 30 and 40 feet (9 to 12 meters). At max size, it was roughly as big as a city bus or an adult Trex.
However, despite its huge size, Otodus chubutensis had to share the seas with the much bigger Otodus megalodon. Based on the tooth similarities between the two megasharks, we can speculate that chubutensus also feasted on whales, so it may have competed with Megalodon for prey.
Now, as you know, Megalodon was the biggest of all these megasharks. Maybe not as big as some movies suggest, but definitely as big as most living whales.
Even as babies, Megalodons were massive. In the womb, baby Megalodons ate their siblings, which allowed them to gain mass before they entered the ocean.
In the ocean, infant Megalodons were no smaller than 3.5 meters (11 feet). That’s over half the size of the largest great white on record. Most modern sharks that size can seriously injure or kill a person, so a baby Megalodon was dangerous right out of the gate.
Young Megalodon lived in nurseries in warm, coastal waters, and they probably ate a diet similar to great whites. We know they lived in nurseries because paleontologists found multitudes of “tiny” Megalodon teeth in great numbers in Panama, Florida, Maryland, and the Canary Islands. Giving birth in nurseries is a behavior common in many modern sharks.
When the juvenile Megalodons finally matured into adults, they became even more formidable, growing over 30 feet (9 meters) long, which is slightly larger than the largest killer whale on record. Fully grown, a Megalodon was probably half the size of a blue whale, but the largest fossilized teeth suggest they could grow larger.
Their exact size range is still up for debate. We went from thinking they were nearly 100 feet in the early 1900s to 43 feet in the 1970s to 80 feet in the 1990s to 60 feet in the 2000s to 50 feet in 2019. To 60 feet again in 2021.
Of course, all of these size estimates are so wildly variable because all we have are teeth. If you know a thing or two about sharks, you’ll know they don’t have bony skeletons like most vertebrates. Instead, their skeletons are made of cartilage, and cartilage does not fossilize well at all.
Generally, only their hard, calcified teeth are preserved. That’s why we rarely find shark skeletons, even from sharks that are alive today. So, unlike a T-rex, where we have all the bones to estimate size, scientists can only estimate Megalodon size based on their teeth.
Now, since we only have teeth to estimate a Megalodon’s size, how the heck do we know what they looked like? I mean, their teeth look pretty similar to a great white’s so they should basically be oversized great whites, right? Wrong. We have no idea what they really looked like.
Because of this uncertainty, Megalodon has been jumping from taxon to taxon. Megalodon is unique among prehistoric life because we use its species name to describe it rather than its genus. Not many people are out here saying, “Rex” instead of T-rex or Tyrannosaurus.
Surprisingly, we do know a bit about Megalodon’s behavior, even though we only have teeth. We know Megalodon ate whales and other large marine mammals because we have fossils whales and pinnipeds with cuts and breakage that match Megalodon teeth. Additionally, we found Megalodon teeth in or near these fossils.
We also have an idea of how they hunted based on how these megasharks damaged the bones of these marine mammals. Megalodon hunted prey based on its size and species. For smaller whales, it targeted the heart and lungs for an instant kill. For bigger whales, it targeted the whale’s tail to immobilize it and cause it to bleed out. For raptorial sperm whales, it targeted the head, breaking the whale’s strong jaws and sharp teeth.
But, while whales were often food for Megalodon, some whales were the exact opposite. In the Southern Hemisphere, a megaraptorial sperm whale known as Livyatan hunted and ate other whales, and it may have even hunted Megalodon. This whale could attain lengths over 50 feet (15 meters), which would certainly rival Megalodon, and it had the most powerful bite of any tetrapod.
Yet, despite all we can draw from Megalodon teeth, we still don’t know exactly why they disappeared, although scientists have a few theories.
First, the Central American Seaway closed between 5 and 3.5 million years ago. This was basically a natural Panama Canal, so when it closed, it blocked marine travel between the Atlantic and Pacific. This, in turn, cut off the warm Gulf Stream current, so it could no longer enter the Pacific.
Second, whales were getting bigger and traveling away from the warm tropical seas into the frigid polar ones. This made it hard for Megalodon, which preferred warm water.
Third, great white sharks and killer whales were both rising up through the ranks in the ocean food chain. Both of these predators would’ve been a snack for an adult Megalodon, but they ate the same prey as Megalodon and may have even eaten Megalodon babies.
Contrary to what some cable channel documentaries claim, Megalodon has been dead for a long time. Up until recently, scientists believed Megalodon had died out 2.6 million years ago, but in a 2019 estimate, Megalodon’s extinction date was pushed back to 3.6 million years. That doesn’t bode well for any claims of a Megalodon surviving today.
Sure, the ocean is vast and deep, and a Megalodon or two could’ve sought refuge in a trench somewhere. But, in order for a Megalodon to exist in modern times, it would have to either elude all humans near the surface or elude all humans in the abyss. Neither scenario is likely. Big predators need a lot of food, and Megalodon was voracious. If it lived near the surface, there would be dead whales littering our beaches with massive, unmistakable bite marks. If it lived in the abyss, it would starve due to the scarcity of large prey in the deep ocean.
We should be thankful these megasharks are now extinct. If they still existed today, the course of history would be much different. Our relationship with the sea is already perilous and complicated, so adding a literal sea monster to the mix would further muddy the relationship.
Would it be cool to see a living Megalodon today? Yes. But, just like our relationship with the dinosaurs, we should be careful of our desires. We’re better off loving and appreciating Megalodon from the safety of millions of years of separation.