How the Squid Lost Its Shell

Published on Apr 17, 2018
The ancestors of modern, squishy cephalopods like the octopus and the squid all had shells. In ancient times, their shell was their greatest asset but it eventually proved to be their biggest weakness.
Special thanks to Franz Anthony for the beautiful cephalopod reconstructions. You can see more of Franz's tremendous work at
And thanks as always to Nobumichi Tamura for allowing us to use his wonderful paleoart:
Produced in collaboration with PBS Digital Studios:
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  • CONGRATS ON THE PROMOTION!!! working for PBS now!!! I am stokked to see Sci show's host on PBS!

  • Love this guy keep being awesome also love crash course (cc) helped me in college

  • Wait..squids have 8 legs 😱😱😱

  • What if centaurs could talk?

  • It became a kid, then a squid, then a kid, and then more.

  • "We're here for a good time not a long time boys!"- Ammonites

  • the ancestors of lord helix.

  • *I don't know why I always laugh out loud when I see the "feet" as measure of lenght next to meter system. It's just so damn stupid :D... "feet"...*

  • Where did that first gas come from?

  • I feel like im learning the history of pokemon....

  • My favorite historical animal is the "Ammonite"

  • It is a biggest mistake of a Cephalopods , if the Cephalopods still have it the whales will choke on e'm, I wish the giant squid have one so the sperm whale cant eat it :D

  • 6:15 "While Octopuses" "Octopuses" *"OCTOPUSES"* um excuse me sir

  • This channel rules!

  • Did you steal this video from scishow are was it make here first?

  • *Gasp*, Hank’s cheating on SciShow?!

  • YAY! It's Hank!!! :)

  • Splatoon

  • Reading Squid Empire and this video, along with Soul if an Octopus help develop a better understanding and appreciation for cehpolapod evolution. Great video!

  • Hank Green definitely should be the next person to win a science communicator award. He is on par with Bill Nye, and Neil Degrass tyson in my opinion.

  • there are 9 recorded mass extinctions on earth so far

  • So one floating mollusk started banging non-floating mollusks and make Nautilus?

  • 7:25 First footage squid turf war (2018 colorized)

  • Pretty sure I heard octopus Came From Outer Space?

  • Swimming backwards is stupid.

  • What was the creature that spawned bears and dogs? How long ago?

  • can you make more videos about ancient cephlopopds?

  • Truly fantasmic

  • Woomy

  • I hate those plastic things in the squid when eating them

  • reminds me of something when I was around 7-8yrs old,there's some sort of pond, well, it's more like mini swamp at the back of my school, and usually when I look at the waters, there's small ammonite-like creature, so small, at around the size of the eye's of dragonfly, as far as I can remember it moves just like ammonite explained on this video, and now it got me thinking, what actually are those things? cause my friend say it was "ammonite" back then and i was still young so I belive in it. anyone here got any clue?..

  • ...and then the humans came

  • That's not an upside-down ice-cream cone, it's a squid wizard

  • Ammonite... Omanyte... HMMMMMM Jokes aside this was beautiful, if I were young again I might have gotten into paleontology thanks to this video. 😍

  • So happy you said niche correctly.

  • All of our technology mimics nature in some capacity. In this case, submarines. A nautilus basically has ballast tanks built into its shell.

  • Squidward grandfathers

  • Squizard

  • How do they know squids had shells in the first place?

  • I thank you sir for making this video I like to join you or any scientist. Can you please tell me how can I contact, ask or at least notify you about my curiosities?

  • "Its the Cambrian explosion!"

  • wait, so octopuses are just really smart, floating sea snails that don't have shells?


  • Some of my favorite critters. Thank you! But I will point out that some of the live action 'squid' shots are actually of cuttlefish, their chubbier cousins:

  • poor boy!! lost he hat!!!

  • once i broke a rock and there was a shell fossil inside but then my friend made me drop it and i got mad lol. how rare would it be to find a shell inside a rock u found at school?

  • Fish with jaws Fish with jaws Taking over It wont be long

  • subscribed

  • All hail the helix fossil

  • Plectronoceras is a strapping young man. Nice job lad

  • Nature is definitely my favourite R+D designer.

  • I ate them :(

  • you forgot the awesome tusoteuthis of the Cretaceous period

  • They developed a new way to float,ok why and how? Answer, we don't know yet.

    • +Ben what about natural selection for the why, and mutation for the how, And your hair color is a part of your design, which is clearly not a random process for no particular reason.

    • Theres no "why" it developed. It just happens. Why did my hair change from blonde in childhood to brown in adulthood? You are looking for intent that doesn't exist. Life is not a thing. It is something that things DO.

  • Was anyone else hyped up and thinking yeah you go little guy when they gained the ability to float?

  • Just saying the plural of octopus is octopites for your next video about cephelapods!

  • I want to learn why Bull Frogs are such voracious eaters. I mean they could eat a huge meal in minute and a few seconds later they start eating again. It drives me nuts; and also why do moths fly around so frantically and like to flutter near our legs and clothes?

  • I want to learn about the fossil record, what is it and how is it compiled? Why do people say "modern animals" I've only been able to get cursory knowledge about the fossil record can you go in depth?

  • Awesome video. I wish you were the one that taught me Paleoecology.

  • They might have evolved into a colour changing super-predator, but but can they do it on a cold rainy night in Stoke?

  • I’m no stranger to Latin, but this guy makes it sound simple😅

  • I thought nautilus were extinct tf??😱😭😭😭

  • How does the evolution work? Like that pointy Cephalopod that was 20ft, when it blunted it’s shell, how did that carry on to its offspring?? And how long did it take?

    • Don't they teach you this stuff in school, wtf? This is basic knowledge that every high schooler knows, at least here.

  • He said octopuses

  • squids are dex build

  • Shelled cephalopods look like they are wearing stylish hats.

  • Cthulhu with a birthday hat.

  • So they can change their own body form?

  • PBS Eons Hank Green, DUDE!, from a technical viewpont, you are right more often than that okay to be smart guy (mr. johansson). you is true irl biologist (doing my studies in bio. myself atm), even without degree. because asking the right/more interesting/valuable qu.s more relevant, and because of better formulated sentences (e.g. Scishow stuff, which i know the best because earliest). anyone, correct me if i'm wrong.

  • @PBS Eons, Would you please do a piece on the evolution of spiders. That would be awesome.

  • what happened to Schshow?

  • Did you do bats yet?

  • Actually the only reason us Squids lost our shell is because we use Ink tanks now. Shells held our ink during some wars but with the Invention of new technology we now can use Ink tanks.

  • How did squid, and octopus get so big?

  • The squid at 1:41 looks like it's wearing a party hat.

  • What are non alien dinosaurs? 6:43

  • I'm just going to assume these evolutionary trends happened with Pokémon as well on my journey to become Pokémon master

  • Don't look at my gladius!

  • That cuttlefish reminds me of that cuttlefish I caught a few days ago in Greece. It took me an hour since I could only use my hands. I released it of course but that was after I was done looking at how it breathes and swims

  • Is this the guy from APUSH crash course

  • Hank, what happened to your arms and legs?!

  • Gnomes with tentacles

  • Getting icecream cone in the Cambrian explosion Me: 1 vanilla icecream cone Icecream man: sorry, we only have squid flavour with tentacles Me:I'll pass

  • Hi, I'm just an index fossil, look at me instagram

  • Would appreciate one about raven intelligence, esp how it evolved.Please.

  • to think our beloved squid ward could have looked so different.

  • This is the best counter argument to the conspiracy theory about octopus being from another planet.

  • Did pokemon copy animals or did animals copy pokemon 😒

  • Octopi

  • So they used to be Omastars, so ancient pokemon were real!!!

  • He is so Hot wow

  • Awesome. Fascinating.

  • What was the name of this dudes show? I remember him. It was huge.

  • *U N L E A S H E D*

  • best anime ever

  • I'm so sick of hearing the phrase, "non avian dinosaurs". Birds aren't dinosaurs. Dinosaurs may have evolved into them but they aren't dinosaurs. I hope this fad dies out.

    • because "dinosaur" is a biological term based on how related organisms are, while the purpose of saying "non-avian dinosaurs" is to point out physical differences or talk specifically about the dinosaurs that died 66 million years ago.

    • Then just call them dinosaurs. By your definition they're all the same, so why the specific destinction? When somebody refers to an ostrich they don't call it a non-avian dinosaur, it's referred to as a bird. Although I have heard the phrase "flightless bird", to me it's a bird. Chickens kinda fly, more like fluttering, I've never heard them referred to as "flightless birds" or "non-avian dinosaurs". I'm not saying you're wrong, I just don't like the phrase "non-avian dinosaur".

    • it's not a fad, it's biological fact. that's how science works: you make a definition, and can't just pick and choose which organisms that fit into the definition that you want to be called that. it's based on organisms relation to each other, and since the different types of dinosaurs were just as related to each other as they are to modern day birds that's the definition that makes sense.

  • I would like to know more about dinosaurs, their internal organs, their eyes, their bones, reproduction and why most of them are reptiles and why so many different species evolved.

  • hey its this guy

  • HANK!

  • What the hell was the advantage to having a shell like the nipponite's?