Scariest spider 'really a crab'

[knightjar]

http://news.bbc.co.uk/1/hi/england/manchester/4268363.stm

 

[Wade]

That's intesting, once again a giant fossil arthropod turns out to be aquatic.

I think some of the statements are misleading, though. I don't think the scientist was claiming that it was a crab, only that it's lifestyle was very crab-like. If it's to be grouped with the sea scorpions, it is at least a closely related ancestor to the arachnids, if not an actual spider.

Wade

 

[smalltime]

If it's an ancient scorpion it is an arachnid.... :? isn't it? Ahhh well what do journalists know....!

 

[knightjar]

Apparently it's not as 'scary' if it's not a spider.

Seems like an arachnid to me too. Do compound eyes exclude it's being one? Could they be the precursor to spiders' multiple eyes?

 

[knightjar]

Apparently it's not as 'scary' if it's not a spider.

Seems like an arachnid to me too. Do compound eyes exclude it's being one? Could they be the precursor to spiders' multiple eyes?

 

[Wade]

I can't remember if sea scorpions are classified as arachnids or not. I'll check Polis and post back if no one beats me to it.

I believe horseshoe crabs are related to this group. They're in their own class of arthropods, but they're closer to being arachnids than they are to being crustaceans.

Wade

 

[PapaRoacher]

That sucks that it's not really a spider...

I had always found the idea of a 1m long spider capable of wrapping itself around, and consuming a human head appealing...

 

[knightjar]

I had always found the idea of a 1m long spider capable of wrapping itself around, and consuming a human head appealing...

Sounds like another fan of Alien...

 

[PapaRoacher]

Sounds like another fan of Alien...

Whoa, how'd you know

 

[Crotalus]

The "evidence" seems a little weak:

"It has large claws and two big compound eyes whereas spiders normally have eight small eyes. It also appears to have a very robust body or shell with ridges across its back which is not found in any spider known to man."

http://www.manchester.ac.uk/press/title,15593,en.htm

I wouldnt count this one out just yet.
Fossile taxonomy is probably just a big mess...

/Lelle

 

[Alex S.]

"Sea scorpions" form their own subclass, Eurypterida, within the Arthropoda. Eurypterids, like arachnids, are chelicerates, but "sea scorpions" are not actual arachnids. Some eurypterids, mainly those of the genus Mixopterus, resembled modern scorpions and were believed to be amphibious and ancestral to scorpions (the closest living relatives of the Eurypterida are scorpions and horseshoe crabs). No where in the article, though, does it say that Megarachne belonged to the Eurypterida. No one can say for certain exactly what kind of arthropod Megarachne was, but one thing is certain; ancient arthropods took many shapes and forms just like today's arthropods. It is very possible that Megarachne could be ancestral to spiders like Mixopterus being ancestral to scorpions, although, on the other end of the spectrum, there could be absolutely no relation, other than both simply being arthropods. Studying the correlation between ancient and modern arthropods is, for the most part, very fragmented.

Alex S.

 

[Wade]

Thanks for the sea scorpion info, Alex. After my posting my previous message, I promptly forgot all about it, and didn't bother to look it up. I'm known for that.

Wade

 

[Alex S.]

No problem, Wade. I just wanted to post some of my thoughts on the subject.

Alex S.

 

[Scorpendra]

megarachne not an arachnid? reminds me of basilosaurus the ancient whale. yeah, it seemed a little suspiscious that it looked more like a huge, furry dustmite than a tarantula.

 

[Scythemantis]

Whatever it was, I think many will agree that the mass shrinkage of arthropods over the aeons is a travesty!

If we can't fix global warming, I hope that the resulting mass extinctions and overabundance of algae at least spurs the oxygen spike neccessary to once again support the likes of Meganeuron.