How Did Sharks Survive 5 Mass Extinctions?

Episode 1 of 5



The earliest evidence of shark scales dates back 420 million years which means they survived several mass extinctions. How exactly were they able to do that?

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Sources:

Biology Of Sharks And Rays:

“Checklist of Living Chimaeras: Some 42 species of living chimaera are known, divided into three families."

Sharks:

“There are more than 500 species of sharks swimming in the world’s ocean. Yet when most people think of these cartilaginous fish, a single image comes to mind: a large, sharp-toothed and scary beast."

Shark Fins:

“Bony fish and sharks both have fins that help them to move through the water. However bony fish are able to fold down their fins when they are not being used unlike a shark whose fins are rigid."

Silurian Period Facts: Climate, Animals & Plants:

“The Silurian Period occurred from 443 million to 416 million years ago. It was the third period in the Paleozoic Era. It followed the Ordovician Period and preceded the Devonian Period. "

The Epic History Of Sharks:

“When you imagine a shark, you may think of a torpedo-shaped, streamlined creature with a prominent dorsal fin, a large mouth ringed by sharp, triangular teeth and a crescent-shaped tail. Jaws, basically."

Prehistoric Sharks Escaped Mass Extinction By Diving Deeper:

“The most severe extinction in the earth's history began 252 million years ago, wiping out 90 percent of ocean species and 70 percent of life on land. Modern sharks and their relatives were among the few that survived this "Great Dying," and new fossil finds hint as to how they may have clung on to life."

Sharks Were Once Called Sea Dogs, And Other Little-Known Facts:

“If you were to ask an average person to differentiate between a tiger shark, Great White, whale shark, bull shark or mako, most could probably do so, or would at least be aware that such varieties existed."

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DNews Plus is built for enthusiastic science fans seeking out comprehensive conversations on the geeky topics they love. Host Trace Dominguez digs beyond the usual scope to deliver details, developments and opinions on advanced topics like AI, string theory and Mars exploration. DNews Plus is also offered as an audio podcast on iTunes.

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[soljordal]

I love how enthusiastic Trace is about these topics

[Master_Therion]

I own a megalodon tooth, it's about 5 inches (12 cm) long. That's my "cool shark story."

[randar]

I lived on or near the beach in San Diego and spent days and nights diving, surfing and fishing for 20 years. And not once been bitten or attacked by a shark. Caught 1 leopard shark fishing and seen a 12 to 14 foot white while night diving. Those were my only run ins with them. Sharks have always been my favorite salt water fish. I study sharks, collect fossil teeth and of course watch shark week. My only complaint is the vid. was too short =) Good info, keep up the good work!

[Player_Review]

Thanks for covering up the Apple logo on the laptop with a piece of tape. Macs are gross.

[DirectorFlame]

"420 Million Years ago"
Dank sharks

[michaelstephens]

Warms my heart to hear that 30 Rock reference still going strong.

[Duckaization]

My friends think I am crazy because I willingly went scuba diving with sharks without a cage. I was a little nervous at first when I was standing on the boat looking into the water and saw them circling but once I jumped in and they did not attack me all nerves were gone. My respect for sharks grew exponentially on that dive.

[UnremarkableSteve]

I learned a lot about sharks today, thanks! :)

[cooperbeggs]

I was in the Bahamas on Friday, I was kayaking and a reef shark came up and swam around my kayak! It was pretty cool, once it got closes it bolted away

[CaptainPancakez]

you should add pictures and stuff. get kinda boring just looking at someone talk

[RYV]

On a side note, really, you couldn't have found a larger sticker to cover the whole apple logo on your computer.

[reyshadow]

I go surfing in Hawaii I go surfing in Hawaii half the time, some days there is hammer sharks and we still go surfing

[killer_keebler]

thx for answering that for me was thinking seeker ripped u guys off haha

[dreadrabbit]

will u b touching on the material science relevance of shark scales and how by just thier shape they have antibiotic properties?

[farouk]

hey trace love the show..i'm one of those who watches the vids..can you guys pls include pics and clips in the left corner of the frame pls?

[thebutton]

Sharks are awesome, humans should leave them alone

[caitlinsmith]

When you've got shark week during shark week... :P

[ProjectLee]

how did fish get past the niagara falls into the great lakes we know today? human intervention? glacial activity?

[friedelmajoor]

Is it a Tornado? Are it sharks? Sharknado!

[CorbbinGoldsmith]

The shark's abilities are still dwarfed by the mantis shrimp:

Sees full spectrum light (gamma rays included).
Creates a 3000° vacuum bubble in the water when it closes its pincer.
Cures cancer.