Which Animal Had The First Skeleton? Was it Even An ‘Animal’? GEO GIRL

[@GEOGIRL]

CORRECTION: Okay, so a lot of you point out that my intro (where I say "most animals have skeletons") is incorrect as most animals are invertebrates. However, as as I mention throughout the video, many invertebrates have skeletons, but typically they are exo- (external) skeletons rather than endo- (internal) skeletons, like us vertebrates have. Therefore, while most animals do have skeletons, I should not have said "within our bodies" because most invertebrates have skeletons outside of their bodies, like shells. In addition, many invertebrate animals have no skeletons at all (soft-bodied), like worms. Hope that makes sense ;) Sorry for the poor wording choice there!

[@Dragrath1]

Eh the term invertebrate is misleading as the vertebrate clade has never had a monopoly on endoskeletons and all vertebrates share an evolutionarily speaking "recent" common ancestor which was itself an "invertebrate" meaning the term is polyphyletic and thus cladistically useless. It should also be noted that an organism can have both endoskeletons and exoskeletons One surprising group of animals which have endoskeletons is chelicerates a clade of arthropods of which at least some have cartilaginous endoskeletons which serve as muscle anchoring attachment points. And other "invertebrate" animal groups off the top of my head with endoskeletons include echinoderms and at least prior to the evolution of echolocation in cetaceans strongly selecting against them many cephalopods also had endoskeletons with most barring octopus still retaining some degree of vestigial/reduced/demineralized endoskeletons.

[@uncleanunicorn4571]

I've heard by 1 bya we had an ozone layer leading to our familiar blue skies, but no bony skeletons until 500 mya. Makes me wonder what role the snowball earth cycles had in the availability of the phosphates and calcium needed?

[@footfault1941]

You're not boneless at all! Proved.

[@diebesgrab]

Yeah, my immediate reaction to that wording was: “a-dibba-wha?”

[@Sepi-chu_loves_moths]

​@Dragrath1 correct me if im wrong, but wouldn't that make invertebrates paraphyletic not polyphyletic? Not trying to correct you just curious

[@IsaacKuo]

I love how arthropods were like, "Segments! Segments! And MORE segments!" and in the meantime mollusks were like, "Maybe we should try out a second bone. Let's not get too crazy, but let's see how a second bone works out and maybe go from there. Or not. Two bones is enough."

[@barbaradurfee645]

The most exciting and satisfying ascpect of your videos is that you talk about the evolving interplay between biology, chemistry, geology and phsics at every scale and throughout Earth history.

[@donaldbrizzolara7720]

I would agree. She excels at synthesizing data into a format that is not only understandable and thought provoking but throughout is effortlessly expressed via a very pleasant and cheerful delivery. She has a gift.

[@Antikyth]

I love your presentation style! You talk confidently and in a very easy to process way, not sure exactly how to word it but your explanations are easy to follow. I admit I wasn't sure what the quality of this video would be seeing it had fewer views than most videos in my recommendations but I thought it was a very interesting sounding topic so I clicked anyway... clearly I was wrong to make the association between number of views and quality! You have certainly earned a subscription and like :)

[@beback_]

It's academic style, without extra fluff.

[@donaldbrizzolara7720]

Rachel: I find it fascinating that the first evidence of bony hydroxyapatite is found in the teeth structures of conodonts. A very similar condition is found in ostracoderms but more extreme in that hydroxyapatite went beyond teeth but expanded into an armored structure that encased the head. If one were to cut the cranial bone of an ostracoderm open and observe it microscopically one would find virtually the same mineralogy found in vertebrate teeth. The body of ostracoderms as well as conodonts were boneless. Hence, it appears to me that vertebrate skeletons first had there origins in teeth (conodonts) and head armor/teeth (ostracoderms). Bony body structures came later. Fun stuff to think about.

[@toweypat]

That is interesting, and it makes sense. Evolution often works that way.

[@objective_psychology]

Yup, we all come from exoskeletal fish

[@barryagar3790]

Was the evolution of teeth the beginning of the predator prey ‘arms race’?

[@Marshymilz]

Hey Geo Girl, loving your vids. I am a current 2nd year undergrad in applied geology and they have been a huge help. If you ever have the chance, would love if you could make a vid about your study methods over the years for the geosciences. As I've seen it is the number one thing students struggle with and you seemed to know so many topics from the inside out. Thanks for the awesome content :)

[@SiqueScarface]

Apparently, biologists and geologists have a different idea of what a skeleton is. For biologists, the notochord is a skeleton, because it stabilizes the body and is used to attach muscular tissue. It is not a columna vertebralis (backbone) though, hence animals with only a notochord are not considered vertebrae.

[@zechariah22]

6:30am educational content just hits different

[@duhduhvesta]

10.45 was awesome

[@philochristos]

I always assumed the first bone was a tooth. But it guess it makes sense that it might've been a shell. When the aliens get here, I wonder if they will have exoskeletons or endoskeletons.

[@donnyfanizzi5360]

Thank you. As usual another excellent video

[@jimthain8777]

So you could say that skeletons make up the backbone of paleontology. Thanks for the video, I just love how enthusiastically you present your talks.

[@Pay-It_Forward]

17:00 *This is a no brainer! my expertise is agronomy. Burgess Shale which contains the best record we have of Cambrian animal fossils, has TWICE as much Molybdenum as the crust of the earth & (200 times) as much as Earth's Oceans!!! Molybdenum is required for over 50 enzymes processing & Fixing Nitrogen, plus is needed for construction of many essential amino acids. Plus is needed for phosphate assimilation, plus as a biological catalyst for proton & electron transfer, plus oxygen transfer coupled reactions in biochemistry & phosphorus recycling symbiosis!*

[@harrygoldhagen2732]

Thanks, Rachel, excellent as always! And let me say, as an older viewer, I appreciate that you've slowed down your delivery. The slower (though definitely not slow!) pace really allows me to follow all you are saying and understand it. I'm wondering if you've ever made a video about the beginning of life, especially the theory that life began at hydrothermal deep-sea vents. I've read a few review papers on the subject by Dr. William Martin, but I do not understand the chemistry happening at the vents, something he calls serpentinization (along with a whole lot of other chemistry). Thanks again!

[@GEOGIRL]

Thank you so much! That is good to hear ;) I have made some videos on that, but nothing that goes into the specific chemistry like that, so that is a great idea for a future video, thank you! :D

[@punditgi]

I always love Geogirl videos. Woo hoo! ❤🎉😊

[@v_zach]

If you get a chance, an explanation of why sponges are animals would be interesting. In particular could an argument be made to put them in their own kingdom?

[@Sakkura1]

Sponges are multicellular organisms that can move, especially in their juvenile stage, making them more similar to other animals than anything else. We can also look at their DNA and see they're more closely related to us than any non-animals. All animals have a common ancestor that was likely similar to a sponge or a choanoflagellate. The latter are our closest living unicellular relative.

[@neotericrecreant]

I never even considered such small animals to be capable of "skeletons".

[@Cam_V910]

Good job as always, Skeletons theme might have been fun for around Halloween theme....lol

[@GEOGIRL]

Oh that is a great idea, I wish I'd thought of that lol

[@LiamRedmill]

You got me hooked on the subject again,and I was surprised to see the variety of element's utilized in skeletons,,it's very complex and ongoing with the discovery of new/older fossil's.the use and source of phosphates is fascinating,but is poorly understood as it was eroding field's and bog's and swamp's that fed the oceon's with brackish/phosphates rich living field's(metamorphic.maybe you could explain mineralogically brackish water's from iron/phosphates rich bog's and field's.thanks so much

[@robbabcock_]

Wow, very interesting! I hadn't even thought to wonder about the topic. 💀🐚🐟

[@skipugh]

I love your content. I learn so much.

[@GEOGIRL]

Thanks so much! I am so happy to hear that ;D

[@cw7429]

Very interesting video!

[@Sakkura1]

0:04 Most animals do not have a skeleton inside of them. Invertebrates almost always have no internal bones, and they are more numerous than us vertebrates. Over 90% of animal species, and an even greater percentage in terms of actual numbers of animals. On land, you'll find lots of insects, flatworms, arthropods etc. and at sea you'll also find animals like echinoderms (starfishes etc) and sponges.

[@GEOGIRL]

See correction comment ;)

[@michaeleisenberg7867]

Hello Rachel 🎾, This is a superb video 🎥. Extremely interesting. I loved 🥰 it. 🙏 Have a great weekend 💥🍔🌭🧨! 👏👏👏👏👏

[@michaeleisenberg7867]

Rachel 🐈🥰, It's never a question of will you send me down a rabbit 🐇hole, but which one? Today it was conodonts and chaetognathas (nektonic arrow worms). I think protoconodonts was the common ancestor. Arrow worms 🪱 were an apex predator a few million years before the much talked about, Anomalocaris 🪳.

[@nathanmiller5658]

Fun and facinating video. GG at her best.

[@meesalikeu]

thi is a great topic and just a lot of fun. it also makes you think about ocean world moons around the solar system. especially because the sun didnt really directly come into play with all this until 20min of the 24min video.

[@Dragrath1]

So one important factor which was left out in terms of the origin of mineralized skeletons in animals is the role of scarce essential mineral storage serving as a selective pressure for internal skeleton formation especially in the case of calcium phosphate where calcium plays an essential role in ion action potentials and electrochemical gradients and phosphorus is essential for many critical biological processes most notably RNA DNA and ATP. This evolutionary function is at odds with their use as structural scaffolding in vertebrates and thus biologically plays a key role in bone loss since if a vertebrate can get away without it converting structurally unused bone material into metabolic use is important given the essential nature of these mineral elements towards Earth based life. Anyways in terms of early complexity it might be worth your while to look at the Francevillian biota as the Francevillian basin seems to have had many of the conditions which would spread more globally during the Neoproterozoic some 2.1 Ga. Also from what I have read they don't think the Ozone layer arose until much later or at least if it existed it didn't become opaque to UV C radiation until the Paleozoic timeframe or has that work been refuted?

[@_andrewvia]

The yt closed caption system has trouble keeping up with your vocabulary. I guess it's not trained at a college level. Thanks for another great video. (I have cc turned on because other people I listen to have strong accents (like British or Australian)). You have excellent diction, but the cc still helps me take in your content by letting me both hear and see what you're saying.)

[@_andrewvia]

I see some high-caliber comments - people with a vocabulary as strong as yours, who are here enjoying your videos along with the rest of us mortals.

[@khagan]

When you said "official" at about 5:07, the emphasis made it sound like a pun (of-fish-al 😅)

[@GEOGIRL]

Haha that's hilarous, I wish I could say it was intentional ;)

[@clydecessna737]

Rachel, Could you talk about what indirect evidence there is for life that we have no direct fossil evidence for. What percent of the history of life is known?

[@GEOGIRL]

That is a wonderful question! I will work on a future video over that ;D Thanks for the suggestion!

[@kensounds5177]

the early skeletons could also have begun as a way of storing minerals for later use

[@robertab929]

Our bones are also a partial storage, for example, they store calcium.

[@mickrawson29]

Please do a video on your favourite textbook references and explaining why. In this age of information, it would be great to hear opinions.

[@qazsedcft2162]

19:45 why are you showing a tree at >2Ga? 🤔

[@Poey12]

Crazy thorough, thanks!

[@ewade244]

Ok, ScarJo, the brown hair isn't fooling anybody. I had no idea you had such a rich interest in vertebrates. Ms Johanson never ceases to amaze me. What a talent! 🎥 🍿 🧪 🔭 🐠

[@reidflemingworldstoughestm1394]

Finally, a Geo Girl video for us ordinary mortals.

[@LorenStClair]

You are so cool to keep putting out this Contant, I wish you get to middle school or earlier

[@peterolbrisch8970]

Remember, the average amount of skeletons per person is always more than one.

[@od1452]

First Skeleton.... Already thinking on Sunday Morning before my coffee. Wow....no or not much of an Ozone layer.... I never really thought about that..but I guess that is a good reason for life to start in the water... Boy... bring your sunscreen. Have you discussed the first multi cell organism yet? Thanks good topic.

[@chrisstanford3652]

Excellent synopsis 🤗

[@RichardLightburn]

One of your best

[@ozachar]

So egg shell is an exoskeleton of a single cell? Is there research on the formation process and genetic origin of egg shells in comparison to other exoskeletons in living organisms?

[@whiskeytango9769]

I think that the kick-off was vision, which enabled effective predation, which resulted in skeletonization and armour.

[@uncleanunicorn4571]

Ive heard by 1 bya we had an ozone layer leading to our familiar blue skies, but no bony skeletons until 500 mya. Makes me wonder what role the snowball earth cycles had in the availability of the phosphates and calcium needed?

[@olecranon]

Jellyfish...not actually fish Starfish....not actually fish Shellfish...not actually fish Seahorses...actually fish!

[@Musabre]

Fish....not actually a thing. ;P

[@douglasdingler9405]

They are called fish since people once called anything that primarily live in water a fish. Today people know better, but the language is slow to change.

[@Rico-Suave_]

Great video, thank you very much , note to self(nts) watched 23:49

[@nicholasmaude6906]

As far as I know, Rachel ( @GEOGIRL ), the first creatures with skeletons to walk on dry land were arthropods probably Eurypterids.

[@nicholasmaude6906]

Weren't conodonts sort of a lamprey precursor?

[@shadeen3604]

thanks Dr geo girl great

[@eotheewakan879]

What about isotopes?

[@tessygrondin1271]

Is bark a type of skeleton ?

[@GEOGIRL]

What a wonderful question and thought! This question may warrent a follow up video ;) I mean they are used for protection and stability, just like animal skeletons, so I can't see why not! I will look into it and see if I can't make a video on that ;)

[@jameswright...]

I'd think more likely skin or more protection, armour. Remove it the tree doesn't collapse but it will weep and suffer.

[@neworderadherent]

Life is amazing. I wish we knew more from the time period!

[@Broken_robot1986]

It's not important to be first, just to have fun. What's the first animal just chilling and having a good time? Not sure how that would look in the fossil record.

[@AdrianBoyko]

Decades ago, a friend had a sign above his front door that read “Forsake Ye Your Skeletons, All Ye Who Enter Here!”

[@MrX-nv8kp]

Now i'm wondering, what is a skeleton? Shouldn't cytoskeletons count, too? Why do chordata not count? And why are some shells or armor considered skeltons, but not in others? 🤔

[@GEOGIRL]

That's a great question! Where is the line drawn when it comes to organic skeletons, I have no idea... I guess they have to meet some sort of rigidity and protective standards, but I don't know if these are clearly defined anywhere, good point ;)

[@perceptron-1]

An idea arose: is it possible that calcium deposits in the blood vessels are caused by the destroyed micro-skeletons? A research has to be started on this, and please register my Nobel Prize!

[@robertab929]

destroyed micro-skeletons?

[@gingazaurus]

Very interesting, thanks.

[@jamesdriscoll_tmp1515]

Do cuttle bones count?

[@sailcat9]

Didn't the (possibly predatory) Ediacaran creature Spriggina possess an exoskeleton?

[@emom358]

I just passed it off as youthful enthusiasm until I finished the video.😂

[@Kraflyn]

tldr? what animal or microbe had the very first skeleton?

[@MoonMoon-12775]

Very cool

[@patrickgriffiths889]

Thanks.

[@savagesarethebest7251]

15:40 I wish my computer was quick to point it out

[@IsaacKuo]

Imagine if our fish/tetrapod ancestor line had silica skeletons. "Eat your sand, little Bobby SQL Injection."

[@789563able]

Very interesting. But complicated. Things were simpler when the earth was only six thousand years old.

[@johnbaker1256]

Interesting

[@barryfennell9723]

electron microscope shows the diatoms. i know carbon is an essential element but it makes me think about evolving in-organic fractals that could have been.

[@beachboardfan9544]

Was watching this video the other day and you were the first person I thought of, have you heard of this (I'm sure you have, but I searched your video library and couldnt find anything)? Would you do a vid expanding on what H20 mechanic touches on? I've never heard of this before but I think its fascinating. kzbin.info/www/bejne/oXaqf6J6ltJnoqMsi=dRQW_BhF22hc0viy Around 9:30 he gets into the geology formation thats causing their struggling.

[@whiskeytango9769]

If I had to guess...several seconds into the video...I would guess it was sponges that had the first skeletons.

[@eotheewakan879]

Fish are truly ancient creatures and have always been delicious

[@TheMasonX23]

By skeleton, I mean the spooky, scary kind that send shivers down your spine

[@Saleca]

Better tittle imo "what came first? Animal or skeleton?"

[@rickkwitkoski1976]

Thank you

[@garylister]

'As humans you and I have skeletons within our bodies' could you imagine...yuck!

[@eotheewakan879]

My brain…might have an exo-skeleton but I still watched…most of the video..,when I was paying attention past about 1 millimeters or less…or more carbonate or sicilica or chitin or sharks or cartilage or more radiolarens or Carbonifera~ Thank the goddess of the sea for fish for tacos~I didn’t realize how ancient they truly are and I see salsa differently now!

[@oleksandrbyelyenko435]

Gonna put my 🤓 mode. Most animal are invertebrates so the most animals don't have a skeleton.

[@GEOGIRL]

Well, most invertebrates also have skeletons, they are just exo rather than endoskeletons. So, you're right, I should not have said 'within' our bodies in the intro! Sorry for the poor wording, I've posted a correction comment, see above ;)

[@Sakkura1]

Many invertebrates have a skeleton, but it's almost always an exoskeleton.

[@oleksandrbyelyenko435]

@@GEOGIRL well, yes, I should have pointed out endoskeletons. Anyway, no hard feelings, all in good faith. P.S. I've seen your correction

[@satyammahajan7571]

My friend is a vertebrate but has no spine.

[@sirensynapse5603]

Sleestaks.

[@doriansebastian8065]

I also have skeletons in my body but also in my closet... 😮😢

[@iamKBCummings]

conodont teeth served as geothermomoters.

[@gasdive]

3:22 it's not "insects *or* crustaceans" Insects *are* crustaceans. (Pancrustacea)

[@GEOGIRL]

Oh I thought insects were in the subphylum Hexopoda and Crustacea subphylum was mainly the aquatic crustaceans... I wasn't aware of the Pancrustacea group, cool!

[@gasdive]

@@GEOGIRL I gather that it was reorganised due to molecular information. I'm not sure when though. There have been lots of exciting changes just in the last few years!

[@gasdive]

Look for the video "Butterflies are crustaceans" from "Clint's Reptiles". It's an exciting romp through arthropoda. I can't recommend his phylogeny videos too highly.

[@clintwestwood1895]

Aren't rhino beetles the strongest living thing alive today? and their power comes from in part to their Exo's?

[@slowdownex]

This video is fine, but maybe just a little too slow paced for me. Does anyone else agree?

[@Valdagast]

Could these UV-absorbing pigments have evolved into chlorophyll? Not only absorbing the energy but using it in a productive way.

[@priyanshu95.]

wow

[@thepiper5522]

Fourth!

[@johnvl6358]

😎

[@KIMRT36447]

😊

[@usapatriot444]

Hold on…let’s get the first protocell to replicate. Origin for mitosis please?

[@RuRockhound]

Appetites for apatite.

[@youtubejosephwm6699]

Hey Rachel sorry I don't mean to keep nagging you but I sent you an email

[@GEOGIRL]

I know, I am getting to it, I am so sorry for the delay! For some reason, I have just been getting completely inundated with emails recently ;)

[@youtubejosephwm6699]

@@GEOGIRL okay do you know which email it is

[@GEOGIRL]

@@youtubejosephwm6699 Yep I saw your recent email! :)

[@youtubejosephwm6699]

@@GEOGIRL okay hope to hear from you soon

[@michaelfoster-qw2tw]

Likely stalker?

[@KeithPrince-cp3me]

Maybe it came from a closet.

[@historicalfacts7609]

Are you so cute baby