Oddity Ark #10 (190) Megalodon

At current the whale shark (Rhincodon typus) is the largest extant fish, reaching a modal length of 14.5m and a maximum length of 18m, in the ocean, and much to the relief of everyone it’s a filter feeder subsisting on small fish and plankton. It should be noted that the whale shark isn’t the largest fish ever discovered, that honor belongs to the subject of this issue. Back from the coasts of Pliocene Chile, I present to you Megalodon, (probably) the largest fish to have ever existed.

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Oddity Ark #10 (#190)

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Lamniformes

Family: Otodontidae

Genus: Otodus*

Species:megalodon (1)

* Megalodon has previously been classified in the genii Carcharias, Carcharocles, Cararcharodon, Megasleachus, Procarcharodon, and Selache.

Related Species: Megalodon is one of the 11 species of ‘mega-tooth sharks’ present in the genus Otodus.

Range: Fossils of megalodon are found in sediments across all continents dating between the Miocene and Pliocene periods (23 to 3.6 mya)

IUCN Status: Megalodon is not currently listed on the International Union for Conservation of Nature, but would be classified as ‘Extinct’.

Mega Shark

The exact dimensions of megalodon are difficult to determine due to the scarcity of fossils of cartilaginous fish. More commonly fossilized are the teeth of sharks, with the fossils reaching a length of 18cm and resembling the teeth of the distantly related great white shark (Carcharodon carcharias). Due to the similarities of the teeth, the dimensions of great white sharks were used to determine the megalodon’s size and appearance, with a modal length of 10.5m (34.4ft) and a maximum length of 20m (65.6ft) suggested for the species (2). While most reconstructions resemble a larger and more robust great white shark with blunter facial features, reconstruction of dorsal and tail fin shape based on basking sharks (Cetorhinus maximus) and sand tiger sharks (Carcharias taurus) have also been suggested.

Fossilized remains of whales, sea turtles, seals, and sea cows with the characteristic bite marks of megalodon suggest that the shark species took a wide range of large prey items. Whales, in particular the extinct group of cetothere whales, were the primary food source for adult megalodon, suggesting that the sharks preferred to take smaller prey items than themselves. When attacking prey, particularly whales, the megalodon targeted the heart and lungs, biting through the rib cage to quickly subdue their prey (3). While adult megalodon likely had no predators, the juveniles were prey to the squalodontidae shark-toothed dolphins and the raptorial sperm whales, as well as larger shark species (4).

Using the dimensions of great white shark pups, it's estimated that the pups of megalodon were between 2m and 3m when born (5). Like many extant species of sharks, megalodon gave birth in shallow water coastal areas, where competition and predation were likely reduced. Within these nursery sites, the megalodon pups would feed on fish, sea cows, and sea turtles while they matured and moved to off-sure environments and fed on whale species.

Sundown89 Urban Legend Quashers #4: Megalodon Lives!!!

Statement: I’ve heard of megalodon from a documentary. From what I recall it’s still alive and stalking the oceans.

Fact: That documentary has a lot to answer for. Megalodon went extinct 3.6 mya ago due to global cooling. As the climate cooled (6), whales grew larger to survive cold temperatures when harvesting plankton in the polar regions. With large prey all but absent, the megalodon was outcompeted when hunting smaller prey by ancestral killer whales and the great white shark.

Statement: Nah, megalodons are all hanging out in the Marians Trench.

Fact: Water temperature in the Marians Trench ranges from 4°C to 1°C (39°F to 24°F), temperatures akin to those found in both the Arctic and Southern Oceans (7), places where megalodon couldn’t survive. Also, there is a reason why all abyssal megafaunal predators such as giant squid (Architeuthis dux) and sleeper sharks (Somniosus pacificus) are all ambush predators that rarely move. If it’s akin to a great white shark, the megalodon would have a metabolism too high to survive on little food.

Statement: But we’ve only explored 5% of the ocean, there are plenty of places megalodons could hide.

Fact: Okay so we’ve mapped almost 20% of the ocean (8), far more than 5% than commonly stated. Additionally, a large surface-dwelling predator like the megalodon would be quickly discovered, especially since humanity has been seafaring for millennia.

Statement: But what about the two teeth found by the 1875 HMS Challenger expedition? They were dated as being only 10,000 years old.

Fact: The dating method only tested the manganese dioxide (MgO₂) levels within the teeth which is considered a flawed method. Modern radiocarbon dating found that nitrogen levels within the teeth are too low to be reliably dated.

Statement: But…I saw it in a documentary….

Fact: That Discovery production ‘Megalodon: The Monster Shark Lives' is a fictional piece of work masquerading as a documentary. Almost all the data presented in this production are unfounded and were made up by the Discovery channel.

Statement: So Megalodon is extinct…

Fact: Would you want it to be extant, that would be terrifying if it was still swimming the ocean.

References

1. www.arkive.com

2. Pimiento, C.; Balk, M. A. (2015). "Body-size trends of the extinct giant shark Carcharocles megalodon: a deep-time perspective on marine apex predators". Paleobiology. 41 (3): 479–490

3. Prothero, D. R. (2015). "Mega-Jaws". The Story of Life in 25 Fossils. New York, New York: Columbia University Press. pp. 96–110

4. Lambert, O.; Bianucci, G.; Post, P.; de Muizon, C.; Salas-Gismondi, R.; Urbina, M.; Reumer, J. (2010). "The giant bite of a new raptorial sperm whal-e from the Miocene epoch of Peru". Nature. 466 (7302): 105–108.

5. Pimiento, Catalina; Ehret, Dana J.; MacFadden, Bruce J.; Hubbell, Gordon (2010). Stepanova, Anna (ed.). "Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama". PLOS ONE. 5 (5): e10552.

6. Pimiento, C.; MacFadden, B. J.; Clements, C. F.; Varela, S.; Jaramillo, C.; Velez-Juarbe, J.; Silliman, B. R. (2016). "Geographical distribution patterns of Carcharocles megalodon over time reveal clues about extinction mechanisms". Journal of Biogeography. 43 (8)

7. "The Temperature in the Mariana Trench". Infoplease. 28 February 2017

8. Nearly 20 percent of Earth’s seafloor is now mapped - The Verge

Picture Credits

1. gd4ljy602qk51.jpg (2745×1477) (redd.it)

2. R.3b5da5c9bad4fd86347cb3c124c822d7 (1600×1069) (bing.com)

3. R.9746ec5dfdb49e8d3240457dfa5292e1 (1200×800) (bing.com)

4. megalodonWC1-58b5b80a5f9b586046c3405d.jpg (800×600) (thoughtco.com)

If you want to see more amazing animals and plants, please check out the Oddity Arkive for past issues. And if you want even more animals, please check out dearly departed Impurest Cheese’s Guide to Animals which can be found here, or on the blog of long-suffering ecology intern @ficopedia.

@cbishop and @batkevin74

Sundown jumps the (mega-tooth) shark

@sundown89: This was informative and I love your debunking/explanation of psuedo-doco's at the end, great job

@batkevin74: Thanks for the comment.

There is no excuse for spreading misinformation, even about seemingly harmless and mundane things such as megalodon persisting into the Modern Day.

@sundown89: I'll read this after work tonight. :)

Nah, megalodons are all hanging out in the Marians Trench.

I see someone else has read "The Meg."

Seriously though, great article.

@mrmonster: Thanks it’s most appreciated.

I have vague memories regarding the book. So many inaccuracies but I can forgive it for being entertaining and also not presenting itself as Science Fact.

Bump to follow the other topic that has resurfaced

Cool thread. Yeah I think it's cool to theorize and speculate but to label that a fact when alot of these shows come off as speculation more than anything. That actually gives me an idea for a topic...

@arctika: Thanks for the comment and also…

Happy New Year!

Thank you for your article, I have always thought of Megalodons as cool-looking and badass :-) Great White Sharks are cool and badass too!

Ah, I didn't even realize that there was a book called 'The Meg', I thought only the film version existed. I thought 'The Meg' was just made as a film to make a Jaws-like movie but with a bigger shark and with less seriousness and more comedy and more action...like a comedic Michael Bay film, lol.

Ah ok, The Meg novel is a 1997 novel, so I would have been four years old when this novel was published, lol.

@arranvid2: No problem man, thanks for reading. Unless I'm out of the country or hibernating (or we have a special occasion I can relate to wildlife) I release one issue per week about wildlife.

Just trying to carry on my friend and mentor's work that she started here on Comicvine. She covered great white sharks, I can drop a link if you want.

@sundown89: You're welcome and Thanks! Happy New Year to you too!