Megarachne the Giant Spider that Turned Out to be a Sea Scorpion
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- Опубліковано 28 чер 2024
- In 1980 the discovery of the largest spider that ever lived was announced and this new big spider was named megarachne. However, 20 years later it was found to not be a spider at all and was actually from a now extinct and ancient lineage of creatures called eurypterids. But this arguabley means that this creatures evolutionary history is even more fascinating because it lived almost 100 million years after the eurypterids had their hay day and looked very different from these creatures.
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I found this channel randomly and
It was a eureka moment
Eurekaryote
Me too
@@ccriztoff eureka is ancient greek for i have found it
I found it searching octopus evolution a day after he uploaded squid evolution
Praise the algorithm
Megarachne, but:
*It is not an "arachne", it's a sea scorpion.
*It is not so mega, but relatively small among sea scorpions.
*It is not a scorpion, but closely related to them.
*It didn't live in the sea, but in the fresh water.
Actually given the revelation that Horseshoe crabs are unambiguously true arachnids it suggests that the eurypterids which have morphologically long been placed as more closely related to arachnids than horseshoe crabs probably actually are arachnids after all
academic.oup.com/sysbio/article/68/6/896/5319972
zslpublications.onlinelibrary.wiley.com/doi/am-pdf/10.1111/jzo.12493
@@Dragrath1 that's super cool, thanks for the info
@@Dragrath1 horseshoe crabs arent arachnids, though they are closely related. It is a xiphosuran, the family of horseshoe crab. Sea scorpion are more closely related to arachnids but too they arent arachnids
@@RMSLusitania Check the links in my post that was the old view which has been overturned by molecular phylogenetics. So they really are arachnids unless you want to make arachnids a paraphyletic grouping.
The connection has been suggested going back hundreds of years but this also helps explain a large number of peculiarities such as how baby horseshoe crabs need to breath air. xiphosurans and early Eurypterids also share this characteristic as the majority of fossils of these organisms are their molts they leave/left on the shore in order to spawn. It is kind of bizarre for a marine animal to be unable to breathe in water until after their first molt.
Both groups also possessed the UV fluorescent cuticle which is strongly tuned to fluoresce the ultra high energy UV C radiation that doesn't reach Earths Surface anymore. And yes the UV fluorescence patterns survive fossilization.
Probably the strongest evidence is the morphology of the "hood" of hooded tickspiders a lineage of soil dwelling arachnids that are neither ticks nor spiders.
Phylogenetically it appears that the "large" and more familiar arachnid clades (i.e. the ones that can be seen to the unaided eye) are derived from within the typically microscopic mites so either arachnids are a paraphyletic grouping or chelicerates excluding sea spiders are arachnids.
Know the evidence isn't foolproof as fossil evidence is lacking and like all groups arising in and around the Cambrian or Ordovician genetic phylogeny is a mess but in the case of arachnids/chelicerates or however they are ordered there is enough developmental/morphological evidence supporting their placement.
Now mites as a paraphyletic grouping of organisms still need further resolution as most species are still poorly studied with likely far more remaining unknown to science.
Fossil evidence is stymied as organisms sized in the millimeter range are poorly known from the fossil record though some promising work finding early bilaterians has suggested that they are likely there if one has the time to screen the grains of sediment in ancient rocks after all how do you identify the grains of sediment that are fossilized animals if they are the same size as a typical grain of sand? Usually we don't pick up rocks unless there is some interesting feature in the rock. The question of where are the tiny animals is almost certainly a question of observational bias as well as preservation bias. Unless you get lucky of have a clear trace fossil to use as a starting point finding microfossils via brute force is daunting. This means that the vast majority of the metazoan fossil record is likely forever beyond our grasp short of some efficient scalable mechanism for identifying microfossils.
As most non parasitic mites today seem to be soil organisms feeding on other invertebrates fungi or other organic material it seems plausible that they were early colonists of the land which would explain the conserved characteristic of UV C fluorescence. There is good evidence from metagenomic sampling that among the large sample of "microbial dark matter" are a substantial number of organisms otherwise only known from marine deposits like foraminifera and of course it seems annelid and nematode worms colonized the land via this intermediary.
@@Dragrath1 its not like arachnids would like evolve into sea scorpions lmao while actual sea scorpions such as Brontoscorpio exist, im talking about the eurypterids not the actual scorpions, and same thing with horseshoe crabs
Megarachne, the sea scorpion whose name means big spider when it is literally none of those 4 things lmao
Scientific nomenclature can range from obvious, to funny, to well...this
Idk, it's still pretty big
@@saucepirate8970 the biggest eurypterid is Jaekelopterus rhenaniae, which could get up to 2.6 fucking METERS. megarachne ain't shit compared to that
The HRE of the animal world
@@zenebean Thalassodromeus sethi is an especially unfortunate case.
I think this time period is more exciting than the time of dinosaurs. The animals are more alien and strange. The Silurian with it apex predator being a ten foot long sea scorpion is just mind blowing. Giant reptile exist in the present time but there is nothing quite like eurypterids. Then in the Devonian there is a titanic struggle between eurypterids, giant cone squids, and jawed fish such Dunkleosteus. Not mentioned in this video there were mushrooms on land the size of trees. This time period isn't really covered too much in science documentaries. Dinosaurs, mammal evolution, and birds get all the attention.
Hang on, what? Mushrooms the size of trees??
I did not know this! Why isn't there kids' dinosaur books that mention this? Or anywhere, really.
This is incredibly awesome to me!
Sometimes what happened and evolved before the dinosaurs is a lot more interesting as nature played around with different designs.
I'm going to go look this up now!
Thanks for sharing! :D
@@TheMurlocKeeper check out the boom “when bugs were big and plants were strange” by Hanna Aidair Bonner
*book
@@Hstat910 Thanks, looks good. But hold on, guy who recommends books.
As I live in Germany and ordering books from the US is rather expensive, I for now collect suggestions like this and make a little list for a bigger order later.
May you have some more good suggestions bookwise? No special era.
@@MegaSockenschuss yeah! Some other good reads are Squid Empire by Dana Staaf or A Brief History of Life by Ian Tattersall. You might be able to find these online
I'm still surprised that Horseshoe crabs are older than Dinosaurs and they still exist!
many things are older than dinosaurs, dinosaurs actually first appeared around the same time as modern mammals, however older mammal species ruled long before the dinosaurs,in the end of the permian mammals were taking over, furry gorgonopsids for example became apex predator, we do not know how they looked but we have dung with fur and their fossils resemble that of modern carnivorans. This was WAY before any dinosaur, even before any crocodilian!
@@trvth1s Yeah, I think modern mammals developed in the Triassic or just before, but the Gorgonopsids were not quite mammals. They are part of the stem-mammals though, meaning animals more closely related to mammals than other extant groups.
Avian dinosaurs also still exist
@@trvth1s Truth is. Not many of those mammals are alive today. and that's what fascinates me! Of course its an aquatic creature and so then like most of aquatic life, most of them survived the Impact. But the chicken is almost as close as a Dinosaurs and so are most birds, and they're still alive today! Which is cool!
Bro wait till you hear about sea sponges
Moth Light Media deserves one million subs. Keep up the great content!
Bin with hin since 5k bro, tell me about It
As evolution shows, good things take time (:
ive been here since b4 5k subs.. He's growing very fast now
Subscribed this channel since it was 1k ❤️
@@jaisanatanrashtra7035 no
I always hope there may actually be a prehistoric spider bigger than the Goliath bird eater to be discovered one day.🙃
@NovaUltimatum Not that I know of.
Probably hiding in Australia
@Something Mildly Homophobic 💀 you know this how?
Their was a giant huntsman spider. Pressed in slate.
There is
Would you maybe do a video explaining the basics of taxonomy? Going over how the discipline works and glossing over the important families and things you need to know, I feel like I would enjoy your videos a lot better if I had that background knowledge...
Also i would love a deep dive on the evolution of the first predators.
Anyways, thanks a lot for the great videos, you really awakened my interest in this field!
Aronra made a grear series on the subject
ua-cam.com/play/PLXJ4dsU0oGMLnubJLPuw0dzD0AvAHAotW.html
I dont think taxonomy is what misses for the full understanding of these videos. Instead i would recommend to seach for systematics knowledge: study about understanding how philogeny works and how to interpretate them, study about definitions of monophiletic and non-monophiletic groups in a philogeny, what are sister-groups and out-group, and characters polarization (this one is a little more complex but shows if you really understood the basics of sistematics). Taxonomy by itself is only the naming of the organisms, these names arent easy to memorize, especially without the understanding of their philogeny (their evolutionary process). Sistematics will make you understand how evolution works and how to understand the organisms evolutionary history.
I dont have many references in english (because im brazilian and not because they are rare, quite the opposite, there is much more references in english than in portuguese) but i may search for some if you want me to.
@@pedroquinellatodantas9669 I would love to read some literature about these things if you could recommend any...
The last time I was this early, this spider/scorpion was still around...
you sir have got an ISP better than a Butler
I remember watching BBC's Walking with Monsters when it had recently come out, unaware of what Megarachne actually was. They casted it as a relative of mesothelae spiders (one of the most prehistoric lineages of spiders still alive). I was so disappointed to find out that the massive spider was never real, although sea scorpions have also always fascinated me. Here's a suggestion: make a video on the evolution of spiders! And include what the largest known true spider was.
These doesn't answer what the true history of spiders is but it suggests they have been around probably on land for a long time.
academic.oup.com/sysbio/article/68/6/896/5319972
zslpublications.onlinelibrary.wiley.com/doi/am-pdf/10.1111/jzo.12493
The largest known true spider ever is the Goliath bird eating tarantula.
I loved that show.
@@metoo3342 tarantulas are not true spiders
@@meowmix4jo then what are they
Congrats on 100k subs!!!
This Video is like a perfectly timed 100k subs special
so its like the platypus, the last member of its once much mighty lineage.
Super neat!
Well, I don't think he was implying that freshwater eurypterids were that rare at that point. Just that they'd gone extinct in the oceans. Campylocephalus survived until the Late Permian - en.wikipedia.org/wiki/Eurypterid#Carboniferous_and_Permian
And of course, the fossil record is always incomplete, so there could have been some survivors after that too!
No there are 4 other in the Monotreme family (egg laying mammals) still alive today, the platypus is just the only one in that family that is aquatic. Also all in the family produce milk from glands but they have no nipples, the young lick the skin which secretes it on stimulation. The Monotreme family is very intruiging.
Shoutout to the person that subscribed to your patreon as Ken Ham. You're a legend.
Who's that?
Wait why would Ken Ham support a channel about evolution, lol.
I absolutely love your videos. It feels like I'm in a different dimension looking back into the prehistoric world. Thank you for every video you make.
Megarachne, a carboniferous eurypterid. My favorite!
Very educating, entertaining and calming videos. Sometimes I even fall asleep to your vids just like bedtime story. Hats off to your great work sir.
This arthropod might have a living style same as some kind of amphibious arthropods like crawfish or coconut crabs but more likely to living in swamp.
Thank you so much for focusing on these very early creatures. I am glad we still have the horseshoe crabs today. Great video! Thank you
Yay a new moth light video!
I really enjoy your content man usually my end of the day chill out time.
They phylogenetic tree at 2:17 isn’t entirely correct - the Trilobita are actually more closely related to the Chelicerata than the Hexapoda, and Crustacea is now known to be a paraphyletic clade.
Myriapods are also now known to be less closely related to Hexapods than most “Crusteceans” are. The cladogram shown in the video has been rejected in favor of the Pancrustecea hypothesis.
Fascinating as always. I remember seeing a cast of this critter in a museum in Australia back in 1999 along with (erroneous) giant spider art.
Congratulations on passing 100,000 subscribers, it’s very well deserved :)
Congratulations on 100k
One of he’s video from a year ago got recommended to me and now i is addicted
Congrats on 100K! Looking forward to seeing more of your videos!
I’m glad you are still making content
Love your channel man! Ancient animals are SO captivatingly fascinating!
Your channel is incredibly professional and interesting. I can't wait until you blow up
100k!!! Congrats man
Congratulations on 100K! You create great content you deserve it.
I am so happy to see you've reached 100K! I found you via reddit when you had 1% of what you have now!
Fantastically put together. Thank you
Fantastic content, as always!
Congrats on 100k subs!!!
You know, all your videos are somehow very therapeutic for me.
Not only are they educational, but your videos help me go to bed with ease.
Congrats on the 100k! Totally deserved, your vids are great!
Congratulations for the 100k, been here since like 12k I think, you really deserved this
Yooooo, 100k subs that’s real good
I know right.
Congrats on 100K! This channel is awesome
Im always excited to see a new video of yours in my feed when im playing Civ or something :D
Wow, congrats on 100k! I love to enjoy your videos while I'm drawing or working
Congtats on 100k subs! This is my favorite biology channel :)
Congrats on 100k!!!
Love it. thanks for this video
Excellent video! It's refreshing to have the names repeated multiple times throughout. Megarachne and Eurypterids. Feels like I've actually learnt something! :)
You're at 100k already congrats!
That invertebrate phylogenetic tree is a bit outdated.
Hexapoda isn’t the sister group of myriapoda, it’s suppose to be nestled within crustacea under a new group called Pancrustacea
Yess, and Myriapoda is sister-group of Pancrustacea, both members of the taxon Mandibulata
Ya, you kids forget that we learned KPCOFGS. And then shortly after I graduated high school that all changed. Right about the same time this "little fellow" was being reexamined. So the scientific analysis is going to be all over the map. Certainly not saying you are wrong, but he lists his sources and in their time they were solid sources.
@@pedroquinellatodantas9669 Also worth noting that the other group of extant chelicerates Xiphosura(horseshoe crabs) have been discovered to be true arachnids nested deep within the arachnid family tree as a sister group to Ricinulei the hooded tickspiders (which are neither ticks nor spiders despite their name).
academic.oup.com/sysbio/article/68/6/896/5319972
So it seems the distinction of chelicerates being seperate from arachnids has been called into question. In particular it raises the question of whether eurypterids may also have been true arachnids a lineage that may adapted to life on land before the ozone layer existed(thus explaining why have UV florescence).
The arthropod family tree has been radically changing with molecular studies
That was simply beautiful! And except the introduction - brand new knowledge!
I always expect to be enlightingly entertained - to be given brand new knowledge from you, that was more than I thought I'd find here!
Usually I am more than happy to learn a mere quirk of what I already know - brand new knowledge, so beautifully granted - is beyond what I would've ever ask for!
Thank you! ❤️
Congrats on 100k subs! 🥳🥳
This channel is great!
Thank you for the content
Congrats at reaching 100 thousand subscribers you deserve it
hi,good video, you can do a video about the evolution of mamals or the evolution of the running crocs
He did on the running Crocs I'm pretty sure, might be wrong though
Make it a 100k subscriber special.
Oh yeah the Hooved crocs would be interesting to learn about.
You need to check out PBS eons. They have already did it
Congrats on 100000 subscribers!
I love how your channel brings extinct fossils to life. Not only do you discuss their anatomy and physiology , but also their ecology. It's fascinating to imagine how ancient food webs would have operated.
You're videos reignited my passion for paleontology that i have somewhat lost after studying pharmacology at uni. Thank you moth light as I now read both paleontology scientific articles such as the recent one by Cooper et al on megladons size while also readying ones on Pharmaceutical Chemistry. You deserve many more subscribers
Congratulations, you have reached 100 THOUSAND subscribers!!!!!
Your dialog is amazing. Thank you. If i could add, you should include a constant visual timeline on top of all your videos so people can have a better understanding of the transition of time.
Very nice! Well done, and quite pleasant and relaxing.
Very nicely done as usual. Thanks.
cheers from overcast Vienna, Scott
Great video!
Fantastic and fascinating video💖💖💖
I just subbed. Great videos! :^)
Amazing vid as always 😊 I'd love to see a video on the hoatzin and it's evolutionary history. That could be really interesting to watch. Just a suggestion tho.
Congratulations for getting 100k subscribers
You deserve more subscribers
Always brilliant info .🇪🇸
Thank you I’ve been wanting to learn more about the sea scorpions
i rejoice every time you upload. know that. you actually have a place in the lives of people all around the world.
You should make a video about Myotragus, the extinct cold blooded dwarf goat of the Balearic islands
I heard about that thing. It was absolutely !!!! Didn't it also have front-facing eyes?
Interesting channel however in this area there have been some major discoveries that suggest the initial classification as an arachnid might not have been as wrong as it was thought but in a very unexpected way.
Recent genomic studies have shockingly found that robustly phylogenetic models including a full diversity of arthropods consistently place horseshoe crabs deep within the arachnid clade.
academic.oup.com/sysbio/article/68/6/896/5319972
More specifically they have found tseparatearachnids having conventionally branched off before the split between true arachnids and eurypterids. If Horseshoe crabs actually robustly nest deep within the arachnid family tree as a sister group to tick spiders then this naturally means eurypterids would have to have been true arachnids after all as the alternative cladistically means that excluding horseshoe crabs from arachnids would require that most familiar arachnids such as spiders ticks scorpions camel spiders, harvestmen etc all must be excluded as arachnids. In summary evidence is building that the conventional order of cladistics is not supported by genetic studies as with exception of sea spiders all other chelicerates actually nest within arachnids rather than being the other way around with the most basal members of the arachnid family tree being the microscopic mites which are found basically everywhere in the planet living off pretty much anything imaginable. This kind of makes sense in retrospect as mites are far more diverse but raises challenging questions as it suggests unlike the classical picture the terrestrial arachnids came before the later aquatic forms. Did arachnids arise underwater and then independently colonize land in every lineage except horseshoe crabs and eurypterids? And if so why do the latter two appear fully formed suddenly in the fossil record?
Or perhaps just maybe arachnids were true early colonizers of terrestrial or inter-tidal environments? After all this would better explain why Horseshoe crabs need to return to land in order to breed. This trait is otherwise only shared with species which returned to the water millions of years after adapting to a terrestrial lifestyle. Of course there is then the real problem that the ozone layer did not exist meaning UV radiation reached the surface unimpeded radiation which is damaging for most life.
There is however independent evidence in favor of this latter hypothesis which would go lengths to also solve one of the modern enigmas of biology related to one peculiar trait seen in some modern Arachnids like scorpions possess namely their strong florescence of high energy UV radiation. Nowadays this trait is perplexing since the wavelengths that they fluoresce don't naturally occur on Earth anymore as they are blocked by the Ozone layer.
However if arachnids arose on land back in say the Early Cambrian this no longer would be a mystery the florescence could be a natural defense mechanism against the dangerous UV radiation of the sun. The most basal arachnids are the diverse families of mites all of which tend to be extremely tiny fairly similar in size to the definitive bilaterian burrowing fossils of the Ediacaran. What if some of those colonized the land far earlier than we have thought?
The best evidence I have come across for this is this paper zslpublications.onlinelibrary.wiley.com/doi/am-pdf/10.1111/jzo.12493
Here the author Dr. James Lamsdell identifies UV florescence adaptations analogous with those in modern Scorpions and other arachnid orders within fossil horseshoe crabs and eurypterids suggesting that UV florescence is plesiomorphic among these organisms due to the conserved molecular level structure. The most logical conclusion then is these are all organisms which arose in Terrestrial environments and then recolonized the oceans like the various marine reptiles from mosasaurs to sea turtles sea snakes and penguins to pinnipeds and cetaceans.
A third incidental line of evidence for this has to do with where eurypterids first appeared namely in shallow seas to perhaps inter-tidal brackish environments only later adapting into free swimming forms. Their initial appearance in the fossil record is in the Ordovician occurred at a time where conditions on Earth were in flux due to the sudden onset and termination of glaciation which seems a perfect environment for a lifestyle shift back to marine ecology so perhaps megarachne was a member of an ancestral sister group that never left the land.
GREAT VIDEO.
I once saw a depiction of it. Its was basically this but it had posionus porcupine like quils, similar to the tarantualas defence of shedding its irritating "hair". and it live in a swamp. Imagine you are walking through the carbiniforuus, and you are attacked by giant millipedes, giant proto reptiles/amphibians, giant dragonflies, giant pretty much everthing!
I've found the rear part (7cm total, 4 segments) fossilized in northern Spain in the mountains...my only animal fossil ever!
Great stuff
Nice editing
I never knew that it was the Great Dying that took out the eurypterids, intersting
Increíbles vídeos! Disfruto trabajar con ellos de compañía 😁
I love prehistoric animals and creatures in general. I watch documentaries all the time, but I prefer these videos. His voice is so niCe.
This makes Mirelurks even scarier actually, that 2 meter fresh water crab 😵
I love the eurypterids nice vid man I love your content. Well at least in this case a earlier not as ancient relative.
Megarachne is so interesting and also its family line.
Hey Moth! Are you ever going to do dinosaurs like Ornitholestes ever? Cause i kinda wanna know what it ate (i know sauropod were apart of its diet but i need to know *more* ) and how it loved if it lived eith predators and everything else you can say, cause you and Trey The Explainer are the best people i love watching (i watch eons too but eh you guys are my mains)
What's the name of the music you use in video? It's lovely
thanks for new nightmares
Thank you for these enormously interesting videos on evolution and paleobiology. Your channel is what Ben G Thomas' channel could have been and what PBS Eons should have been.
"there were spider traits that the creature was missing, or traits that spiders have, which megarachne was missing" isn't that the same thing twice?
shift in perspective, that particular nit probably don't need to be picked
@@entropicflux8849 I think the second makes more sense cause it never belonged to the spider family though the basic shape was still like a spider
Like the video this is so cool.
I love ur Videos im binging them at the Moment, i just read Improbable Destinys by Jonathan Losos, it is about Convergent Evolution,thats how i found ur Channel. Thank you for feeding my brain.
"sea scorpian" fix this before too many people notice
UPDATE: it has been fixed but moth light didn't acknowledge my contribution
What is a scorpian?
Also "Typical spider traits that the creature was missing, or traits that spiders have, that megarachnid was missing".
Ehm, yeah?
Sounds like this video was produced a bit sleep deprived.
lmao
@@rogerwilco2 scorpiOn
“C squorpeon”
Gary Oak nyan scopyan
can you do a video on stegosaurs and reltives
The swimming eurypterids experienced a downfall due to a universal climate change, it lead to glacier and caused the decrease of sea level, which killed most members of Pterygodia, and the rest of them didn’t continue spread but grow bigger with less numbers, giving the chance for fish grow bigger and eventually replace their niche(since most of Pterygotus shared the same niche as predatory fish like shark, but they were limited by their size since arthropods have to mote)
there was a recent study from early 2019 that showed that horseshoe crabs are within arachnids.
it used full genome data and multiple models to explain the anomalous result that horseshoe crabs being arachnids, but all models show it to be within arachnids and most of them say its a sister group to hooded tick spiders (ricinulei)
Megarachne: what I get when I run out of face wash and start using Radox 3 in 1
Got a sub from me love history and science so yasss
I remember this Sea Scorpion, and even at this point, it's still an amazing prehistoric sea scorpion,that happens to be also a giant spider (not).
Brilliant job on pronouncing all tho's names.
That's a cuttlefish at 5:40. In one way are those and squid related. Ooh, time for a rabbithole.
Cool
Hope you do a video about lesser known primitive snakes (like the madtsoids)