August 16 – Chomp!

Today’s factismal: The megalodon shark died out about 2.5 million years ago. No matter what the Discovery Channel says.

If there is one thing that Star Trek teaches us, it is that some sequels are worth watching (e.g., Star Trek II: The Wrath of Khan) but others are a waste of good popcorn (e.g., Star Trek III: The Search for Plot). This year, we’ve gotten two from the latter category. First, SyFy aired Sharknado 2: The Second One which, to be fair, spent a lot of time joking about the first one and actually had a grain of science at its root (in the same sense that a nursery rhyme might reflect politics). But then Discovery Channel doubled down on last’ years debacle and decided to re-air  Megalodon: The Monster Shark Lives complete with yet more “evidence” of that the shark still “lives”.  Of course, given that the Discovery Channel’s “evidence” consists mainly of statements from scientists that were obtained under false pretenses and have been taken out of context and heavily edited, you shouldn’t place much reliance on them. To put things as bluntly as possible, the Discover Channel’s show wasn’t science, it wasn’t entertaining, and it wasn’t worth a megalodon’s coprolite.

A megalodon jaw, seen from the side (My camera)

A megalodon jaw, seen from the side
(My camera)

But there’s always a bright side to this sort of nonsense, and here’s the bright side for this one: it has gotten people to talking about one of the world’s coolest sharks. Megalodon (bio-speak for “huge tooth”) is mostly known from fossils of its teeth, which are typically about the size of a dinner plate (explains the name, huh?). In addition to their teeth, fossilized megalodon skeletons have been found, thanks to the fact that they had a partially calcified skeleton instead of the pure cartilage skeleton of most sharks. Though they looked a lot like a Great White shark on steroids, they were probably more closely related to the Mako (though this is still controversial in the paleontological community).

My nephews get eaten by a megalodon (My camera)

My nephews get eaten by a megalodon
(My camera)

So how big did a megalodon get? Let’s put it this way: you’d need an aquarium the size of the Gulf of Mexico if you wanted to keep one as a pet. A full-grown megalodon was up to 60 ft long and four of them would weigh as much as a blue whale. And that’s not surprising, considering that they mostly fed on whales and any other large animal foolish enough to go swimming in their neighborhood!

A megalodon hunts his prey at the Houston Museum of Natural Science (My camera)

A megalodon hunts his prey at the Houston Museum of Natural Science
(My camera)

Unfortunately for them, their prey needed large, warm, shallow oceans to thrive. And as the climate changed over the past few million years, those places became harder to find. As a result, their prey either died off or adapted to deep water existence. And when a critter’s food source goes extinct, that critter’s end isn’t far behind. As a result, the last of the megalodons died about two and a half million years ago.

But we are still finding megalodon fossils in places like Florida, Spain, and Morocco. And we’re finding all sorts of other fossils, too! If you’d like to find some of your own, why not join PaleoQuest or your local mineralogical society?
http://paleoquest.org/10.html
http://www.gcgms.org/

3 thoughts on “August 16 – Chomp!

  1. The Megalodon still exists, but probably shrined down in size. I doubt that there are many left and I suppose if they would die out tomorrow no-one would notice. So basically it is more or less all about the cult, the believe, that it might still exist and the fun searching for it.
    Yes I am a Megalodon fan and maybe I am absolutely wrong with my claim that they are still alive. But I believe they might live their hidden undercover life in the abyss until this day…
    Who knows for sure…? It’s a myth!
    I don’t even wish for it to be scientifically proven too much or some dumbasses would try to hunt these awesome animals down until they became diminished. That would be a pity. If they get rediscovered it should be kept a secret!
    By the way, I am pretty sure they feed on diving whales and orcas, they would never attack humans, that would not be worth it for them…
    They probably turned so small, they could also be mixed up with great whites or other big sharks…
    And no doubt, that the Discovery Channel is faking most of its evidence for their stories! Everybody knows that. But that’s neither a proof nor an anti-proof…I’m just saying’…
    Thanks for reading, sincerely your Megalodon fan

    Luis

    • I’m sorry Luis, but the evidence is that the Megaladon died out some two and a half million years ago. This is based on three important things:

      First, the Megaladon’s main prey (baleen type whales in shallow environments) had become much scarcer. Think of it this way: If the fridge in your kitchen is stuffed full of food, then you can have a lot of people over for dinner. But if you’ve only got a can of soda and a stick of butter in the fridge, you can’t feed nearly as many people. That’s what happened to the Megaladon; suddenly the all-you-can-eat buffet of baleen whales turned into a grad student’s kitchen and there simply wasn’t enough food around to support a large population of Megaladon. And that then meant that the poor shark went into a long, slow decline that ended in extinction.

      Second, the newest evidence for Megaladon is two and a half million years. There are no fossils of the teeth or jaw that are younger than that. No preserved bite marks young than that. No coprolites. Nada. Megaladon isn’t Architeuthis which has a benthic life style and feeds mainly on small benthic prey (and was still known by trace fossils long before we caught one). Megladon is a cosmopolitan littoral predator; it lived in shallow waters across the globe and didn’t have much in the way fo range limits. If one exists, it should have been seen by now.

      Finally, the ecological niche filled by Megaladon has been taken in large part by the largest dolphin out there, the killer whale, and to a lesser extent by great white sharks. Both killer whales and great whites feed on the same prey that used to fill Megaladon’s gaping jaws: whales and seals. That is strong evidence that the predator that used to fill the niche is no longer around because there simply aren’t enough of those food beasts around to support three different apex predators (four if you count man).

  2. Pingback: January 18 – Not A Drop In The Ocean | Little facts about science

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