# Giant Prehistoric scorpion



## signinsimple (Feb 14, 2008)

I put this up in another thread then thought it made sense to make an independent thread.  If anyone cares about scorp history, not too long ago they  unearthed the largest prehistoric scorp yet known.  It was a sea scorp (where they all came from) that measured 8 feet long (Called jaekelopterus rhenaniae). . heres a link to the info on bbc if anyone is interested:
http://news.bbc.co.uk/2/hi/science/nature/7104421.stm

Apparently, this scorp is close to 2 feet longer than the largest one previously known (I thought the largest previous fossil found was 3 feet long, but i guess they found a 6 foot long one after I read about the 3feet long one a few years back).  Anyway, the implication is that scorps (as well as other arachnids, insects and crabs) were much larger in the past than we had once thought.


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## Trexer (Feb 14, 2008)

Wow facsinating


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## mrbonzai211 (Feb 14, 2008)

That is true, but is not possible in the modern day. Bugs in general breath through book lungs and depend on oxygen saturation in the air to allow them to breath. Back in prehistoric days, there was MUCH more oxygen in the air which allowed the size of bugs to increase exponentially. With sea faring creatures go, I have no idea if there is a similar dynamic here so I have no idea why invert in the ocean stay so relatively small. I guess I would probably assume that they are limited in size due to predation and being small means it's easier to hide.


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## lucanidae (Feb 14, 2008)

Ok....a couple of things here. First, that's a Eurypterid. That is not a scorpion. The current thought is that Eurypterids are a sister group to the scorpions, it in no way 'accepted' that they are the predecessors of the Arachnids. Still, it's cool that they found one so large!

On the topic of size:



> Bugs in general breath through book lungs and depend on oxygen saturation in the air to allow them to breath. Back in prehistoric days, there was MUCH more oxygen in the air which allowed the size of bugs to increase exponentially. With sea faring creatures go, I have no idea if there is a similar dynamic here so I have no idea why invert in the ocean stay so relatively small. I guess I would probably assume that they are limited in size due to predation and being small means it's easier to hide.


There's a couple of misconceptions here and it's propagated by the poor interpretation of the discovery by the person who wrote the article. First of all, 'most bugs' do not breath through book lungs. 'Most bugs' going on diversity and species number use trachea. Also, the O2 saturation hypothesis is only that, a hypothesis. It has just as many flaws as other hypothesis and not much supporting data. At this point it's correlation...not causation. Also, it doesn't apply here because this animal was aquatic, and the O2 saturation of the oceans hasn't changes nearly as much as the atmosphere. Inverts in the ocean don't really stay relatively small, there are plenty of huge aquatic arthropods, including giant isopods, giant sea spiders, and absolutely enormous crabs. Under the pan-crustacea hypothesis (which is well supported) insects are actually just highly derived crabs....so really the size of this creature probably has no implications for the size of ancestral insects...and probably not for most arachnids either, especially considering it's only 390 mya...that's only 40 million years before the first Mesothellidae fossils were found. It's hard for me to believe that in a minimum of 40 million years the entire arachnid clade evolved from Eurypterids.

As for not being possible today, in a closely related group you have a giant land anthropod called Birgus latro and an even larger aquatic one called Macrocheira kaempferi.


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## Xaranx (Feb 14, 2008)

lucanidae said:


> At this point it's correlation...not causation.


Exactly.  There's a lot we don't know, but we do know there was more oxygen in the air back then, and we do know this species existed back then, but that doesn't make the two directly related.  

Nevertheless, it is cool and who knows what is waiting to be discovered in the ocean depths that isn't just a fossil.


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## signinsimple (Feb 14, 2008)

lucanidae said:


> Ok....a couple of things here. First, that's a Eurypterid. That is not a scorpion. The current thought is that Eurypterids are a sister group to the scorpions, it in no way 'accepted' that they are the predecessors of the Arachnids. Still, it's cool that they found one so large!


I've not heard that, but I have read many articles that indicate the popular belief in the scientific community is Eurypterids are the predecessors of modern day scorpions (none have said that they are the predecessors of all arachnids)



lucanidae said:


> Also, the O2 saturation hypothesis is only that, a hypothesis. It has just as many flaws as other hypothesis and not much supporting data. At this point it's correlation...not causation. Also, it doesn't apply here because this animal was aquatic, and the O2 saturation of the oceans hasn't changes nearly as much as the atmosphere.


Lets keep this discussion honest.  If the O2 air saturation is just a hypothesis, you cannot possibly know how the O2 saturation of bodies of water have changed over time.  Besides, water absorbs oxygen from the air, so if the air had more oxygen, the water would have too.  Especially if these guys lived a semi aquatic lifestyle and spent most of their time in shallow water.  



lucanidae said:


> It's hard for me to believe that in a minimum of 40 million years the entire arachnid clade evolved from Eurypterids.


  Agreed.



lucanidae said:


> As for not being possible today, in a closely related group you have a giant land anthropod called Birgus latro and an even larger aquatic one called Macrocheira kaempferi.


Coconut & Japanese spider crabs are big, but they are mostly legs (it's the legspan rather than the body size that is impressive).  They are generally dwarfed by their prehistoric cousins (and this sea scorpion).

Good discussion.


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## Trexer (Feb 14, 2008)

Who knows what is at the very bottom of our oceans, we know more about space than we do about down there, there could be giant creatures like the giant squid


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## Gr8Reptile (Feb 15, 2008)

What about a giant sea millipede!  OOHHH OHH!!! And it could excrete acid and the divers that discover it! One guy gets his face melted off! I just know it is at the bottom of the sea. And when it happens they'll make a movie remake called the 
Millipede massacre
And you guys will post how amazing it was that I was right!!!!! MWAHAHAHAA!!! Whee... Did I mention the Sea Millipede melts a guys face off? That makes me so happy .


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## Kugellager (Feb 15, 2008)

signinsimple said:
			
		

> Lets keep this discussion honest. If the O2 air saturation is just a hypothesis, you cannot possibly know how the O2 saturation of bodies of water have changed over time. Besides, water absorbs oxygen from the air, so if the air had more oxygen, the water would have too. Especially if these guys lived a semi aquatic lifestyle and spent most of their time in shallow water.


Actually, that is not true.  In places where there are evaporite, precipitate and biologically derived minerals one can, in many instances, determine what the oxygen content of the prehistoric atmosphere and ocean was by the examination of elemental and isotope ratios.

John
];')


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## ChainsawMonkey (Feb 15, 2008)

Ok, for all we know(not stealing Trex's idea just adding on) they could still be down there, I mean, we've only covered a total of 1% of the deep ocean floor and trenches. And it's SUPER cold down there. A lot of you don't know this about me, but I'm also a fish enthusiast (that's how I know this). Now, back to what ever the heck water temp has to do with size. I know a ton about sea inverts and fish and whanot, and most of the time, tropical fish are small because of the low O2 dissolved in the warm water, and typically live 5 years or less. But coldwaters like goldfish and koi, well, they can become monsters! Provided with at least 1000 gallons of water at 35ºF - 68ºF with a slightly alkaline ph, most goldfish (those little ones at the fair, nothing special) on average, reach around 16 - 23 inches by their 2nd birthday, and live anywhere from 10 - 40 years. Koi provided with identicle conditions, grow on average to 2 - 3 FEET and the longest lifespan attained (so far) is around 210 years. Then there are your coldwater inverts like snails, temperate shrimp, and crayfish. They don't live as long but do attain similar lengths and appetites as goldies and koi. There are those little mystery snails that they sell at walmart for a little over $1, and as long as the water doesn't drop to 40ºF or below, they can grow to around the size of an apple. Then there are freshwater crabs that grow to over 3 feet in legspan at the least, and it because they live in cold water. Then there's the world famous Japanese Giant Spider Crab, that attains an adult size of 13 feet or more in legspan, just because it lives in cold, deep, heavily oxygenated water, and lives for a really long time. And there's my two cents.


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## Jer (Feb 15, 2008)

Kugellager said:


> Actually, that is not true.  In places where there are evaporite, precipitate and biologically derived minerals one can, in many instances, determine what the oxygen content of the prehistoric atmosphere and ocean was by the examination of elemental and isotope ratios.
> 
> John
> ];')


This is true and your avatar freaks the poop out of me.


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## ChainsawMonkey (Feb 15, 2008)

sick avi, dude! I <3 clowns.


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## lucanidae (Feb 15, 2008)

> If the O2 air saturation is just a hypothesis, you cannot possibly know how the O2 saturation of bodies of water have changed over time. Besides, water absorbs oxygen from the air, so if the air had more oxygen, the water would have too. Especially if these guys lived a semi aquatic lifestyle and spent most of their time in shallow water.


As someone above said, we actually can. I'll add to his ideas though, in artic ice they can core deep down and correlate dates to depth...then they take samples of the air bubbles caught in the ice and figure out the relative proportions. I mean....if they could find a way to analyze atmospheric 02 levels....it was only a matter of time before they figured out ways to do it for water.


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## signinsimple (Feb 15, 2008)

lucanidae said:


> As someone above said, we actually can. I'll add to his ideas though, in artic ice they can core deep down and correlate dates to depth...then they take samples of the air bubbles caught in the ice and figure out the relative proportions. I mean....if they could find a way to analyze atmospheric 02 levels....it was only a matter of time before they figured out ways to do it for water.


I stand corrected.  let it never be said that I do not admit when i am wrong   This site is cool.  I think I learn something new every time I sign on.


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