Why the Megalodon Shark went Extinct

Published: June 20, 2022 8.29am EDT

Author Michael Heithaus


Imagine traveling back in time and observing the oceans of 5 million years ago.

As you stand on an ancient shoreline, you see several small whales in the distance, gliding along the surface of an ancient sea.

Suddenly, and without warning, an enormous creature erupts out of the depths.

With its massive jaws, the monster crushes one of the whales and drags it down into the deep. Large chunks of the body are ripped off and swallowed whole. The rest of the whales scatter.

You have just witnessed mealtime for megalodon – formally known as Otodus megalodon – the largest shark ever.

In one hand rests an enormous tooth from a megalodon; in the other hand, two teeth from a great white shark. The megalodon tooth is about six times as large as those of the great white.
At left, a megalodon tooth; at right, for comparison, two teeth from a great white shark. Mark Kostich/iStock via Getty Images Plus

About the megalodon

As a scientist who studies sharks and other ocean species, I am fascinated by the awesome marine predators that have appeared and disappeared through the eons.

That includes huge swimming reptiles like ichthyosaursplesiosaurs and the mosasaurs. These incredible predators lived during the time of the dinosaurs; megalodon would not appear for another 50 million years.

But when it did arrive on the scene, about 15 million to 20 million years ago, the megalodon must have been an incredible sight.

A fully grown individual weighed about 50 metric tons – that’s more than 110,000 pounds (50,000 kilograms) – and was 50 to 60 feet long (15 to 18 meters). This animal was longer than a school bus and as heavy as a railroad car!

Its jaws were up to 10 feet (3 meters) wide, the teeth up to 7 inches (17.8 centimeters) long and the bite force was 40,000 pounds per square inch (2,800 kilograms per square centimeter).

Not surprisingly, megalodons ate big prey. Scientists know this because they’ve found chips of megalodon teeth embedded in the bones of large marine animals. On the menu, along with whales: large fish, seals, sea lions, dolphins and other sharks.

An artist's conception of a megalodon shark, with black eyes and a mouth wide open, chasing a pod of striped dolphins.
An artist’s vision of what megalodon might have looked like. Megalodon was found in the warm ocean waters of the tropics and subtropics. Its teeth have been found on every continent except Antarctica. Corey Ford/iStock via Getty Images Plus

Are scientists sure megalodon is extinct?

Internet rumors persist that modern-day megalodons exist – that they still swim around in today’s oceans.

But that’s not true. Megalodons are extinct. They died out about 3.5 million years ago.

And scientists know this because, once again, they looked at the teeth. All sharks – including megalodons – produce and ultimately lose tens of thousands of teeth throughout their lives.

That means lots of those lost megalodon teeth are around as fossils. Some are found at the bottom of the ocean; others washed up on shore.

But nobody has ever found a megalodon tooth that’s less than 3.5 million years old. That’s one of the reasons scientists believe megalodon went extinct then.

What’s more, megalodons spent much of their time relatively close to shore, a place where they easily found prey.

So if megalodons still existed, people would certainly have seen them. They were way too big to miss; we would have lots of photographs and videos.Watch this PBS Eons video and learn more about the megalodon shark.

Why megalodon disappeared

It probably wasn’t one single thing that led to the extinction of this amazing megapredator, but a complex mix of challenges.

First, the climate dramatically changed. Global water temperature dropped; that reduced the area where megalodon, a warm-water shark, could thrive.

Second, because of the changing climate, entire species that megalodon preyed upon vanished forever.

At the same time, competitors helped push megalodon to extinction – that includes the great white shark. Even though they were only one-third the size of megalodons, the great whites probably ate some of the same prey.

Then there were killer sperm whales, a now-extinct type of sperm whale. They grew as large as megalodon and had even bigger teeth. They were also warmblooded; that meant they enjoyed an expanded habitat, because living in cold waters wasn’t a problem.

Killer sperm whales probably traveled in groups, so they had an advantage when encountering a megalodon, which probably hunted alone.

The cooling seas, the disappearance of prey and the competition – it was all too much for the megalodon.

And that’s why you’ll never find a modern-day megalodon tooth.From NatGeo

Why You Should Care Who Wins the AI Race.

Will the Server Farms of today turn into Server Cities to supply the Fifth Industrial Age’s insatiable drive for more computing power?

Or will it be like the Main Frame Computer being overtaken by the PC?

ENIAC (Electronic Numerical Integrator And Computer) in PhiladelphiaPennsylvania. Glen Beck (background) and Betty Snyder (foreground) program the ENIAC in building 328 at the Ballistic Research Laboratory (BRL).

But nowadays the PC in your hand, i.e. your cellphone, offloads it’s computing load to more powerful computers at a server farm. A server farm is actually a large number of PCs hooked up parallelly. All that data has been harnessed in Large Language Models (LLM) to train Artificial Intelligence (AI).

By winning the Fourth Industrial Revolution, Britain was able to produce the ships and tanks that powered their Empire. Whoever wins the AI race (the Fifth Industrial Revolution) will dominate this century and maybe beyond. This thoughtful interview will brief you on the implications of our ongoing competition with China and why we should win, except for one caveat –

this idea of “temporal claustrophobia,” where the Kaiser, Imperial Japan, and Nazi Germany all convinced themselves they were at a high watermark.

Jeffrey Ding

ChinaTalk

GPTs and the Rise and Fall of Great Powers

“Economic power is the most fungible and transferable currency.”

JORDAN SCHNEIDER

 AND 

RYAN HAUSER

JUL 10, 2023

Jeffrey Ding is a professor at George Washington University and the creator of the ChinAI Substack. He argues in a recent paper that great powers must harness general-purpose technologies if they want to achieve global dominance.

In this show, we discuss the historical underpinnings of that argument and apply it to AI today — drawing out policymaking lessons spanning centuries of technologically driven great power transitions. We also get into:

  • Why long-term productivity growth is driven by the diffusion of general-purpose technology, and what makes this so crucial for great power competition;
  • Historical lessons from the UK, Soviet Union, US, and Germany illustrating the cultural and policy roadblocks to tech diffusion;
  • The importance of decentralized systems, and how this helped America win the Cold War
  • Why China’s diffusion capacity lags behind its innovation capacity, and how America should avoid getting locked into any one technological trajectory.

Co-hosting is Teddy Collins, formerly of DeepMind and the White House Office of Science and Technology Policy.

https://embed.podcasts.apple.com/us/podcast/jeff-ding-on-us-vs-china-ai-and-lessons-from-past/id1289062927?i=1000612569365

Midjourney: “Technological Diffusion in the Style of Traditional Chinese Art, City, Society, Schools, Different forms of Technology, Artificial Intelligence, Scrolls, the Printing Press, Computers, Smart Phones”

Click on the 2 page to read the whole interview. It is worth your time to learn about what will undeniably will be the defining driver of our age.

Feeling Hot? Blame a Volcano

NPR chose today to follow-up on a story that literally blew up on Jan. 20, 2022 when the underwater eruption of Hunga Tonga–Hunga Ha‘apai sent megatons of water vapor into the stratosphere, contributing to an increase in global warming over the next 5 years.

TONGA GEOLOGICAL SURVEY TEAM, WIKIMEDIA COMMONS (CC BY 3.0)

NPR picked up on the story today https://whttp://NPR picked up on the story today https://www.npr.org/2022/08/03/1115378385/tonga-volcano-stratosphere-water-warming

EOS noted back in March that the extra moisture in the upper atmosphere would trap enough heat to warm the climate 1.5 degrees in the publication

And Space.com in Marchhttps://www.space.com/tonga-eruption-water-vapor-warm-earth

So while this vapor will eventually dissipate, we don’t know if it will leave any permanent changes to the chemical composition of the upper atmosphere. We do know that the excess warmth will speed up the melting in Greenland that threatens the stability of the gulf Stream and will also release more methane stored in the permafrost.

See What Happens When Barbie and Oppenheimer Run Into AI

You want to see why the writers and actors are on strike?

Because they have seen the future and they are not in it.

This Barbie/Oppenheimer trailer was all made with AI tools that are available to the Public. Yes some of them require subscriptions, but the fees are nominal. That’s how I made this hot date night for them.

Now it is time for your feature Trailer…

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