Giant fossil crab: How did I know there was a crab fossil in the rock? And how did it get in there?!

[@Steph-sk3xb]

Weird to think they were rocks way longer then they were ever crabs.

[@janet.snakehole]

​@@VaporSprite same with me and your lack of punctuation D:

[@anthonycoon6955]

Dude new rocks are being formed all the time constantly

[@5stargrim]

@@janet.snakehole Given that their entire sentence warrants one, maybe two punctuation marks if they want to be excessive.. you not understanding it says more about you.

[@jayjay269]

@@VaporSprite you just couldn’t resist the urge to try and correct someone, only to be as imperfect as the op. Stay in your lane, my guy…

[@Max-zr7hr]

​@@VaporSpritethat's weird it's very easy to read even with the error

[@kugeltmg]

If you identify the rocks by the legs poking out, it may be that there are many complete encapsulated crabs; but with no clear external sign of the contents

[@DeShark88]

That's why I take my portable X-ray scanner to the beach!

[@patrickmanasco5905]

@@DeShark88is this real…

[@legionofsentientcells]

This is a great video. Your explanations for determining signs of fossils within a silt matrix was very insightful and inspiring. Based on your hypothesis for the hydrolysis of this crab, here’s my best understanding of the deconstruction of the crab’s chemical composition (as it’s been exposed to the Ca2+ ions in the water). Note, there are innumerable ions in sea water, so this chemical reaction is VERY simplified. HCO3-(aq) + H2O(l) ↔ CaCO3(s) + H3O+(aq) Bicarbonate (carbonic acid) in an aqueous solution (aqueous just means that a chemical can dissolve in water) reacts with liquid water to form a concretion of solid calcium carbonate and hydronium, which is a weak acid that dissolves easily in water. Crabs and other hard-bodied organisms such as snails, ammonites, mollusks, etc. tend to be very common in the fossil record, as the amount of calcite in their hard outer-shells can easily undergo mineralization fossilization. This is where an organic substance's chemical compositions can react to ions specifically in water to form very tough and hard biproducts, which tend to last the test of time despite the relentless weathering of an ocean/beach environment. Essentially, their chemical compositions are gradually replaced by harder solids, forming a "stone" versions of the once living organism.

[@Rookie_Rockounding]

Dude! The hunt hasn’t even started yet and I’m blown away. One thing I’ve learnt and am still learning is that learning something is so much different to understanding it. I love how you take your understanding and teach it! You can see your passion for this mate! I love it! On with the hunt old chap! (I’m probably older than you but it just sounded cool haha!) okay! Hunt time!

[@Rookie_Rockounding]

I love what your brain does when you pick one up. You take that understanding and explain it to us. So rad! Man I promise you, I cannot wait to fossil hunt with you one day, and be like “okay wait, I know what I’m doin dude, I’ve watched your vids!” And then pull out something awesome! Haha! I guarantee you it won’t go down like that 🤪😂🤣 But one day dude, I’d be so stoked just to find with y’a! One day brother!

[@Rookie_Rockounding]

Yeah nah dude, that was a brilliant vid! Loved it mate!

[@MamlamboFossils]

Ah thanks so much bro!! I always love your comments, so positive 😀 I honestly cannot wait to meet up and do a hunt either, its going to be so much fun! I've got some good agate spots as well, I found some really good ones a month or so back and the most beautiful pet wood!

[@Rookie_Rockounding]

@@MamlamboFossils oh heck yeah man! It honestly would be so flippin cool brother! Man honestly one day dude! That will be awesome!

[@margiebrown7436]

I love watching you both so if you two ever get together there had better be a couple of videos! LoL 😂 That would be awesome!

[@Johnny-Joseph]

I'm really glad you didnt answer these questions in text on the facebook videos! This was super informative!

[@MamlamboFossils]

Yay! Glad you enjoyed it!

[@lenkadobranska1863]

New Zealand really does feel like such a special place :) thank you for showing us all these fossils and explaining how they occur! It's so amazing to watch and lovely to hear as well :)

[@semajguod]

Congratulations to you!! I ran across your interview last night in Newsweek very cool I was like hey I watch this guy all the time

[@hendrikliersch7450]

The important question is: how do you determine which side is "up" when prepping the fossil :D

[@bisquickbilly89]

I was going to ask the same thing

[@modelleg]

The shape of the leg cross-section. The top is the side with the most concavity. .

[@UnstableReaper14]

From what ive seen usually the leg rings on the sides indicate top or bottom. They usually are in the bottom half.

[@MamlamboFossils]

Great question - the leg shape does help as modelleg mentioned, I do still get it wrong from time to time. On the big crab I actually started on the wrong side first :) Sometimes the legs have been flattened which makes it hard to figure out which side is up. The shape of the concretion also helps, usually the are a bit flatter on the top side of the crab.

[@hyfy-tr2jy]

@@modelleg concavity or Convexity?

[@nancywilson9380]

Your theory and explanation of why the concretions are harder than the surrounding material and why it forms the oval shape makes so much sense! You are so blessed to be near the few places on earth that produced these fossils Thank you so much for making this video!

[@MamlamboFossils]

Thanks Nancy! Yip, I really enjoy my time fossil hunting here in New Zealand 🇳🇿

[@impunitythebagpuss]

Such an informative article....beautiful land you enjoy! Thanks for sharing.

[@MamlamboFossils]

Thanks! Im also still learning, hoping to hear some interesting theories from the comments!

[@PI7ABR3D]

That big crab looks so awesome id just love that on a display shelf somewehere. The colouring is great.

[@bfk1970]

I think the crabs fossilizing is unlikely to all be the result of tsunami, there is just too many of them. A more likely scenario to me is that crabs burrowed deeply into mud banks (look at Australian mudcrabs for comparison) and were then killed by something like a storm event cutting them off from the estuary, and drying out and suffocating while buried.

[@MamlamboFossils]

The crabs in holes is an interesting theory. This location was 300m deep so I dont think it would have dried up. Tsunami or earthquakes couod cause turbidity currents. We're probably talking about thousands of events over millions of years

[@richardgipson4023]

You know concrete under the right conditions sets and hardens in 48 hrs . The right chemical mixtures happens in nature all the time . Man figured this out and duplicated it . The only difference is man puts iron in his to hold it together .

[@littlejackalo5326]

There's too many of them? LOL. Have you ever seen how many crabs are walking in the ocean floor? Huge casts, of thousands of crabs, all walking along the floor. One turbidity event could bury 10k crabs at once.

[@mutt3162]

That's awesome. I can't wait to see what is in the possible shark tooth and the bone cluster. New favorite channel right here!

[@MamlamboFossils]

Yay! Glad you're enjoying the channel!

[@mutt3162]

@@MamlamboFossils going to share it with my kids!

[@andrewfannin2795]

Thats the best explanation of how the concretions are formed. Awesome video thank you

[@Biffle-re3db]

I think your theories are logical and sound, but I'm just a layman, but you explained in a way I undetstood. Thanks.! That big crab you uncovered is stunning.💖 Thanks for taking us fossil hunting with you.

[@MamlamboFossils]

Glad you enjoyed the video! Hahaha my sketch wasn't the best though!

[@bread5234]

I'm glad your growing fast and its interesting hearing about these fossils

[@MamlamboFossils]

Thanks so much!

[@brettmartin764]

Your personality is marvelous. And thanks for sharing your discoveries. Pls show opening a fossil or two?

[@lukecoplen8033]

Love watching you enjoy your hobby man!! Question: were would I buy one of these concretions so I can bring out what's inside??? I'd really love to clean up one of these!!!

[@caryolkob8199]

I would love to see your whole fossil collection!! I watched one where you were so excited about a possible penguin. Did you do a follow up on it? I cant seem to find the video if you did. I would like to know😃😃 your videos are very interesting and you get excited about your fossil finds! Thank you for your enjoyable videos!!

[@MamlamboFossils]

My pleasure! I'm still busy prepping the maybe fossil! It will take a number of months to get it done!

[@caryolkob8199]

Thank you for the reply!😄. Now we wait excitingly patient for your results on your super fossil findings. Good luck and I look forward to watching more videos!😄.

[@Lilith-Rose]

Your explanations seem spot on, those are the predominant theories my old geology teacher gave, which matched up with my own thoughts on how they formed, it definitely makes the most sense to me out of all the possible explanations anyway. It's been a long time since I did any chemistry and I never was the greatest at balancing equations so I'm afraid I can't help you there but cheers for putting out such a clear and concise explanation anyway

[@paranolan]

Wow... I'm really jealous. I live somewhere where it is nearly impossible for a layman like myself to find fossils. I'd love to move somewhere like New Zealand some day. This channel is really fun to watch. Keep at it!

[@janvafa9959]

Very cool and well stated explanation about the formation of the concretion.

[@MamlamboFossils]

Thank you!

[@SushiAiBeats]

Was looking around watching Motorbikes and magnet fishing and found this :D really awesome not regretting it one bit . And grats on the find

[@MamlamboFossils]

Thats so weird that you ended up here but hope you like it!

[@alananthony5217]

Just come across your channel. Great videos and very informative!

[@이용현-z3j]

Incredible fossil's finding. it looks like a live crab. It's wonderful achievements. Thanks for your posting. 🌻

[@MamlamboFossils]

My pleasure! Thanks so much for watching and commenting!

[@sandmaker]

A lot of great information, thank you for such a great explanation. It looks like you have several really good collecting places. Be happy, safe and stay healthy. 😷⚒

[@billrobbins5874]

The plant one will be exciting to see. Can't even imagine what it will look like. The crab turned out really nice. Was that a fossil you found by the birds in the trees? Just laying there?

[@mrhomely]

Ok I have a few questions A. How do you keep from scratching or marring the shell vs the rock? B. Is that species of crab still around or is it some proto crab species? C. Do you intend on selling them or just keeping them around the house?

[@catherinebowers3654]

So happy to have found your channel!

[@stephanerolland365]

Awesome video and very interesting theory about formation of nods 😀👍

[@MamlamboFossils]

Thanks so much!

[@andrewclemens2462]

I found a bunch of fossilized whale vertebrae this past weekend. Love your videos, they bring me a sense of peace

[@MamlamboFossils]

Oooh that sounds amazing!

[@sandraanderson217]

I can’t wait to see those prepped! Love your videos. Stay safe!

[@VincentGroenewold]

Very interesting theory. I would find it to be a lot of CaCO3 just from the C from the crab. Seems like it's too much (just by my gut feeling :) ). We have these CaCO3 rocks on the shores of England, so I wonder if it could be a combination of your idea and deposits of shell material. Super interesting!

[@MamlamboFossils]

Im hoping to learn more of the concretion formation from the comments! Maybe if someone does the chemistry maths we can figure it out 🤞

[@hyfy-tr2jy]

@mamlambo Fossils....have you ever considered first making a cast of the concretion then revealing one half of a crab, then cast that side in acrylic then reveal the other side and do the same? this way you could reveal the entire crab and have it encased in an acrylic "concretion" so you can maintain the original shape of the concretion but the clear acrylic would give us an "x-ray" view of how it sat in situ?

[@margiebrown7436]

I think this would be an amazing idea 💡!

[@schnaps1790]

What people forget is that these crabs lived there for millions of years, hundrets of thousand, possible millions of genrerations and only a realy small fration of them got fossilized

[@MamlamboFossils]

Correct, only a minute fraction of animals form fossils.

[@raygrange7312]

Yes such as a tidal wave or mud surge. I think that is a very good hypothesis that you came too.

[@lechatvenere]

Estimations are 0.1% only of the living have been fossilized... The rest, 99.9% just decompose.

[@vandelftcrafts2958]

@@lechatvenere Where do you get these numbers??? if this was the truth we would find many many more fossils. the percentage has to be a lot smaller than 0.1%

[@hyfy-tr2jy]

@@vandelftcrafts2958 Ya....more like something along the lines of 0.00000001% at best

[@Efretpkk]

I'd like a video going over your prepping tools/materials, the fixating agent, the "drill".. What's necessary for someone new to try and prep a fossil :) Thanks for your content, always relaxing and nice

[@MamlamboFossils]

There's not much stopping anyone from prepping a fossil, just start with something small and common 😀

[@andibrown9934]

Agreed! What type/size compressor? Names of the chisel bits, etc. Beginner work shop set up 101. I have some idea of what I would need, but what to ask for or order is an issue.

[@suchnothing]

If you live near a university, you should get in contact with their geology or earth sciences department. When I was at the University of Alberta they had a volunteer program where people could help the university paleontologists prep fossil specimens. You didn't even have to be a student. It's a great way to get experience while working with an expert. I'm sure my old uni isn't the only one that does this. It's also a good idea to talk to them before starting so you can learn about ethical collecting methods and about any local laws around fossil collecting. To go back to my previous example, it's actually illegal to collect and keep fossils as a private citizen or visitor in Alberta. Different places have different laws so you gotta check where you are!

[@WorldofRockhounds]

Your explanation is much more detailed than what I've been telling people haha

[@TheRockEyebrow]

I just saw you in a news article on my phone! So cool!

[@oelschig123]

Fascinating, I was wondering when you would tell us how the mechanics of fossilization works. I'm amazed that you can detect those small leg marks on the rocks. I'm in east London, south Africa. I've tried to find out what fossils we get here but there is very little info that I can find. I have found fossil wood but nothing else.

[@thomasobrien3777]

Really great explanation. This is so interesting

[@MamlamboFossils]

Glad you enjoyed it!!

[@valiantwarrior4517]

That makes a lot of sense about the conception formation. I’ve been trying to think of ways it would happen just through straightforward sedimentation and erosion, but it didn’t quite fit, because they seem to come right out of the cliff like that. My mind was thinking something must happen to change the matrix around the crab and make it more dense. The way the shape fits the crab(etc) does strongly imply that it is having a direct effect on the formation. And the same seems to happen with other similar things like nautiloids, ammonites, clams, etc. All things that would have a lot of carbon in the shell or exoskeleton. Thank you so much for sharing your theories!

[@kski4390]

So awesome. Thanks for sharing your finds and knowledge. Totally enjoyed this video.

[@pandemicgrower4212]

Nice video man! As always much love from the state's 🍻

[@raygrange7312]

I think your theories are extremely good.

[@djokicmetamora]

New Zealand looks pretty amazing! hello from Michigan,USA

[@MamlamboFossils]

It is a beautiful place!

[@gandalfthegrey2171]

This is so cool! I'm subbed! What I want to know is: how do you know where the best spots to look for these kinds of stone fossils are? Do the rocks have to be rounded? There's a beach I love that has some rocks but I don't think they are the right kind... How do you know which beach to go to?

[@suchnothing]

Fossils aren't random, if there's a spot with one fossil, there will often be more hiding nearby! The easiest way to figure out if it's a good fossil spot is to look at local fossil enthusiast groups and see if they recommend that spot. If so, find out what kinds of fossils are usually found there and how to identify them. Different locations will have different kinds depending on what time periods the rocks come from. Good luck!

[@gandalfthegrey2171]

@@suchnothing hey thanks so much for taking the time to reply and let me know! I really appreciate that! Sounds like some good advice :)

[@billrobbins5874]

Just watched again. Big crab looks so nice!

[@MamlamboFossils]

Thanks Bill! I appreciate it!

[@gregoryhancock6057]

@14:00 ... that looks like wheat or barley to me. Amazing when you know what to look for! Now I'm going to have to really pay attention on the beaches around here!

[@Link2855]

I saw so many people calling it fake on facebook, and I had to keep explaining how concretion forms and often contain crabs. I even attached scientific articles on the matter. Some people just can't fathom anything they can't conclude from their knee jerk reaction.

[@brucefulcher9217]

Interesting answers to your 3 most asked questions. A 4th question is: How do you know how to orient the conretion when prepping it? It can't just be good fotrtune that you don't end up prepping the crab's bottom.

[@MamlamboFossils]

I do get it wrong sometimes! There's now sure way to tell. If I expose a claw, I can usually tell which way the ventral and which is the dorsal side.

[@free2er]

Most importat question, how it is possible you have all the beach for yourselves? Here in the UK there is loads of fossil hunters scouring the beach at any time. Great vids BTW. Love to learn some more about preparation process, tools and chemicals used.

[@robertgrimsted877]

Very interesting I was wondering how you did it good vid always good to see a happy person doing good vids god bless

[@Madmen604]

Very interesting. Where did you find them? I'm in Canada on west coast, from the east coast. Lovely beach, but sharks yes. I heard there are great whites off Nova Scotia. We are getting fin sightings closer to the beach and never heard of that before!

[@MamlamboFossils]

New Zealand 😄

[@never2late454]

I was told that the crab's hibernate during winter by burrowing in the mud by creating a small oval chamber . Sometimes they die during this time and minerals fill in around them and turn the chamber into rock over time. I don't know if that's true but it sounded like a reasonable explanation at the time.

[@NewZealandRocksDownunder]

Being calcium carbonate does that mean that acid could be used to expose the crab?

[@MamlamboFossils]

Acid is used to remove the rock but it will attack the crab as well. Fossil bone is usually okay though.

[@timtaylor1365]

I think your theory is the best explanation, you've studied this in depth and are very knowledgeable and expert so I cannot think who is better qualified to explain

[@MamlamboFossils]

I wouldn't call myself an expert, very much an enthusiast! I've read a few papers and it matches with what I have seen as well 😀

[@lindalewis5066]

You draw better than me. 😂 Great explanation on how the concretion is formed. I didn't know the carbon from the decomp participated in it. Never too old to learn! Plant fossils are a great find. I love the New Zealand countryside. I miss the ride-along's! 👍❤️

[@QueenOfShovels]

Oh man......New Zealand looks stunningly beautiful! I could fossil hunt there all day every day😍 how fun! Just found you and can't stop watching your videos! New sub👍

[@LouseGrouse]

Would love an update in future on any info about that fossil plant imprint

[@MamlamboFossils]

I've had it ID'd as a Norfolk Pine type species by a paleobotanist.

[@LouseGrouse]

@@MamlamboFossils cool! Any ideas on how old the fossil is?

[@MamlamboFossils]

@@LouseGrouse its mid-Miocene so around 12myo

[@LouseGrouse]

@@MamlamboFossils Amazing stuff

[@chamalowchoko]

Formidable ! Merci pour les explications 😊

[@ulpilotrmh]

Can you give the details on the tools you use to reveal the fossil imbedded in the rock? Enjoying your videos.

[@MamlamboFossils]

It's an airscribe, google the CP9361 model

[@mikes5637]

Nice one. I had asked some time ago how the concretions are formed around the crabs. Long time since I had a science lesson.

[@ronpatriot6679]

Clearly, the filming of your exposing the crab was time lapsed, but how long did it actually take to end up with the finished product?

[@outdoorsy01]

The fossil crabs you find are spectacular!

[@drbushnaqable]

How do you stabilize fossil bone ? What you use ?

[@MamlamboFossils]

Paraloid B72

[@041nic]

Great explanation, makes sense to me 👍

[@MamlamboFossils]

Thanks so much!!

[@ksajak]

Going back and watching some of your past videos. My son loves your channel! He loves fossils!! And he loves crabs! I was trying to figure out the best way to reach you because I wanted to see if I could purchase a fossil from you for my boy. He would be ecstatic!! If you get this please let me know the best way to reach you. Thank you so much!

[@MamlamboFossils]

Hi Kyle, email me at [e-mail] - I don't sell any fossils. Also let me know what country you are in.

[@soniainacio6580]

Awesome video. I will look now with more attention to the rocks in Portugal beaches. We have a lot of fossils, from Dinosaurs Thanks for sharing!

[@crackthefoundation_]

Thank you for the mineralization, explanation. Victorians thought animal shapes just happened randomly in nature and that was their explanation for fossils, for a time.

[@MamlamboFossils]

I'm glad you enjoyed it!

[@johnhunt2390]

11:40 What is that rock your hammer is laying on? What makes that pattern?

[@victoriadorsett7358]

My gen chem is a *little* rusty but would the chemical equation be Ca + 2HCO3 -> CaCO3 + H2CO3 ?

[@MamlamboFossils]

Oh wow! Thanks so much for that!!

[@terrencejohnson1584]

I'm kind of disappointed you didn't open any of the new ones

[@MamlamboFossils]

They're in the queue

[@Whateverhasbeenmynameforyears]

with your explanation I would wonder if bone concretions are harder/different/more common because they have the Ca already there.

[@sera6755]

I know this is response with the comments on that fb page where your vid was featured. If you guys have read that comment section, you would feel your braincells dying. Keep up the cool vids.

[@MamlamboFossils]

From what I have seen, way less people thought it was fake in this video. There was a bigger proportion in previous Facebook videos - hopefully the knowledge is spreading!

[@lynnscott8286]

What is the clear product you put on as you loosen something from the rock

[@suerobertson5132]

Hi from OZ,,, love ur channel,LOVE ur office , have u ever had to run from a land slide? and if so did u find anything from it?

[@robingw2615]

Very informative video Thanks 👍

[@ElevenBravOH]

Have you ever done just half? Opposite of the horizontal plane you did on this one...leave half completely in stone, with the other exposing the crab (left vs right). I love your work, sir. I know you're a busy guy, I wish you had your own series on HISTORY or even BBC doing what you do on multiple continents with different specimens ❤

[@MamlamboFossils]

I'd love to teavel around and do this 😀 i havent done a half like you mentioned. I have done a half crab though that was broken

[@jaextc]

..Or even better a front excavation. I really would like to see the face of these little sea bugs.

[@outoftheforest7652]

what do you use to paint on so you can write on it?

[@SteelCurious]

can you exhume the entire crab? like not keep any gray behind or does it just break?

[@IratePuffin]

I’m still amazed by that giant crab!

[@lookship]

V interesting dude keep it up 👌

[@MamlamboFossils]

Thanks mate!!

[@aserta]

That plant impression was very cool under the microscope. I have a few from Tunis, never occurred to me to scope one, i'll have to dig up my biology trunk. :)

[@MamlamboFossils]

It was Craig that first saw the plant material! He is really good at figuring things out 😀

[@jordonz555]

Shared knowledge from the locals also helped 😉

[@MamlamboFossils]

It sure does!

[@ccccarriemchardy9216]

I agree with your theory about volcanic or a cataclysmic activity. I reckon liquefaction plays a part in the process.

[@MamlamboFossils]

Thats a good point! I think there were some Miocene volcanoes around 😀

[@markharris4421]

So the concretion "grows" using the carbon from the crab? Do you think the crabs were alive when buried? It's always intrigued me that most of your crab fossils are so complete. Love your channel mate, fascinating stuff.

[@MamlamboFossils]

Thanks Mark! I think there is a decent chance some of them were buried alive. If you imagine an mudslide going through a huge crab colony, some of them would have been alive for sure!

[@markharris4421]

@@MamlamboFossils thanks for the reply! Hope you find that penguin!

[@michaelrobertson8795]

Good information👍✌

[@EmbraceTheJourney]

I live in Washington State. Now you'll have me looking for crabs in rocks

[@MamlamboFossils]

Hope you find something!

[@siddartha11]

Washington fossils are mostly Ordovician. They are primarily in the northwestern part of the state. Good luck, I hope you find something.

[@EmbraceTheJourney]

@@siddartha11 we live in Olympia, but traveling to the north is always nice, we will be on the lookout for fossils

[@siddartha11]

If you do a Google search for Fossils in Washington PDF you can find a copy of pamphlet published in 1953 that shows fossil deposits and what areas they are in. There's a lot more than I thought.

[@RichardRickettsAtty]

Thanks for answering my biggest question, but in the course of answering your question, i have a more important one, as i am in Washington State. Where in Washington State can I look for these crab fossils when I am at the beach?

[@MamlamboFossils]

Sorry, I have no idea of the specific locations and whether they are even at the beaches

[@jimmyzhao2673]

Is it possible to use some kind of x-rays to see inside of the rocks ?

[@stuart5042]

Do you think it's possible to find something like this in the UK?

[@MamlamboFossils]

They do find fossil crabs in the UK

[@jeffbaran8036]

Great video. Many thanks my friend. Peace

[@AaronChristensen]

More prep videos!!!!!! I love this one too lol.

[@seanparchim9165]

A pleasant Sunday afternoon watch

[@MamlamboFossils]

Nice!! Glad you enjoyed it!

[@peggylosacco8811]

Thank you ever so much for teaching..us how it works..

[@MamlamboFossils]

My pleasure!

[@bonesstones6584]

Man I love New Zealand lamb chops, only chops from New Zealand, lamb from Australia and the USA taste like crap. Awesome plant fossil, a pinecone is on my bucket list. Lastly, loved the footage at the end, those little birdies look like time travellers, poof dissappear from here, now I'm over here!

[@alext7074]

Ca will combine with HCO3 to form Ca(HCO3)2. The calcium bicarbonate at high temperatures (a common thing deep underground) will decompose in CaCO3 + H2O + CO2. Not sure if this is what actually happened but that's the chemistry of what you described.

[@mattg6333]

As a sedimentologist, you are partially right. But the carbon does not come only from the fossil. Most of the time, CaCO3 (formed from HCO3- and removed a H+ give you CO3 --, which is a perfect receptor for Ca++) need a core or a nodule to be fixed on. That is why, most of the time, there is fossile inside a concretion. If there is nothing inside, the former fossile may be dissolve or just nothing.

[@Dohcaholic]

Hey Morne! where did you get your legend hat??

[@videowatcher674]

Very well done. I think this type of animal may have first appeared during the Cambrian period or about 542 million years ago. A more detail description of Geological Time Periods would better tie down a better date. Possibly, Ice Age periods would add to the information.

[@biggsherm100]

I love watching your videos on KZbin. Now whenever I go to the beach I want to find a crab so so bad. I am currently in Northern Japan. Do you know of anywhere I can find something like that in Japan as you mentioned?

[@MamlamboFossils]

Yeah totally! Have a look in the description of the video. I linked to the paper in the Nature journal where they talk about the Japanese concretions. I'm not sure if they show the exact location. Just read up on the local laws as well, not sure what they are like.