new wolrd and old world... a few qu's about it

peterspiderling

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ok, i have come to notice a few things about new wolrd and old world and wondered why? so anyway...

1. new world have iratating hairs and old dont
2.old world e.g. P. Regalis (males) have no mating hooks and the new wolrd males do.
3. venom, old world seems to have worse venom then new world...

so is this because...

A. old world were around before new and have evolved in to new wolrd and some didnt?
B. different types and though selective breeding and area they live in came 2 different types? (since new world tarantula seem to come more the west and old world the east)

so i just want some light on the situation really :D

thanks for any replys i get!

Pete :D
 

Drachenjager

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the truth is there isnt a soul on earth that can answer that question with certianty.
But , since NW Ts have ulrticating hairs they may not need such potent venom for defense. Most things that would eat them would rather not get an eye full of ulrticating hair. OW ts on the other hand have these pesky things that eat them called humans, maybe they need venom more potent to humans and semians for that reason.
remember that all the land was at one time gathered into one place and it seperated out to form the continents as we have them now. so being seperated that far with differant survival needs may well have adapted to thos differant conditions.
not sure that addressed all your questions but ...
 

Pulk

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1. new world have iratating hairs and old dont
2.old world e.g. P. Regalis (males) have no mating hooks and the new wolrd males do.
3. venom, old world seems to have worse venom then new world...
how accurate are these generalizations? (i know they're a lot truer than the opposites but still... just wondering. not saying you got anything wrong.)

A. old world were around before new and have evolved in to new wolrd and some didnt?
"old world" and "new world" refer to when white people discovered the continents... not enough time for species differentiation there. :)

B. different types and though selective breeding and area they live in came 2 different types? (since new world tarantula seem to come more the west and old world the east)
"selective breeding" is something humans consciously do... but the area thing -is- a very important factor in evolution/speciation - ones in different areas survive better with different traits, if that's what you mean...

new world is the americas
old world is eurasia and africa
australia doesn't count
 

WARPIG

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the truth is there isnt a soul on earth that can answer that question with certianty.
But , since NW Ts have ulrticating hairs they may not need such potent venom for defense. Most things that would eat them would rather not get an eye full of ulrticating hair. OW ts on the other hand have these pesky things that eat them called humans, maybe they need venom more potent to humans and semians for that reason.
remember that all the land was at one time gathered into one place and it seperated out to form the continents as we have them now. so being seperated that far with differant survival needs may well have adapted to thos differant conditions.
not sure that addressed all your questions but ...
I believe that this sums up any basic assumptions one can make regarding the differences between OW/NW.

Well put!!!
 

ShadowBlade

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1. new world have iratating hairs and old dont
First off, not all NW's have urticating hairs. Psalmopoeus spp do not, (consequently, they are closer related to the Old World family Selenocosmiinae then to any other NW species.) There are others, such as Tapinauchenius. The reason NW's have them and OW's don't will take many years of research, possibly its different predators, habitat, or behaviour.

2.old world e.g. P. Regalis (males) have no mating hooks and the new wolrd males do.
Wrong. Many species of NW males do not possess them, and many OW's do. There should be no generalizations here.

3. venom, old world seems to have worse venom then new world...
There could be a correlation between possessing urticating hairs and venom potency, however again you're making generalizations. And there are more species then we have in the hobby, with more or less venom strengths.

Pulk, Aussie tarantulas are considered OW's.

-Sean
 

Pulk

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First off, not all NW's have urticating hairs. Psalmopoeus spp do not, (consequently, they are closer related to the Old World family Selenocosmiinae then to any other NW species.)
That is pretty cool.

Pulk, Aussie tarantulas are considered OW's.
That may be, but Australia isn't necessarily considered as being in the Old World. :}
Why are they considered OW? If it's because of their behavior and urticating hairs, we are getting dangerously close to circular reasoning.

-Jacob
 

sick4x4

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and i wasnt aware of the aussie's possessing urticating hairs???? maybe some clarification is needed...cough Michael Jacobi cough lol......
 

Pulk

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and i wasnt aware of the aussie's possessing urticating hairs???? maybe some clarification is needed...cough Michael Jacobi cough lol......
sorry, i didn't mean to imply i thought they had urticating hairs... i have no idea.
 

sick4x4

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sorry, i didn't mean to imply i thought they had urticating hairs... i have no idea.
no worries i didn't know either way:liar: ..MJ helped bring these guys to the states, soo i figured if anyone could weigh in on them he could...

i know we try not to generalize OW and NW but to be honest like stated somewhere above??? NW and OW has more to do with regions then defensive mechanisms...though we can speculate as to the whys, whats and maybes , its still all hypothetical... sadly though, we can make correlations to each species of t and make it fit somewhere else but to be honest OW and NW is just an easy way to identify overall regions....... this way we don't have to identify each and every country when trying to describe a T.......think of it like cliff notes......but then again i would be generalizing :rolleyes:

i think aussies are generalized as OW because they exhibit traits much like the C. crawshyi and other baboons....or we could just call them future world T's?????;P
 

dragonblade71

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All countries outside of the Americas are considered 'Old World.' From what Ive read, Australian tarantulas do not possess urticating hairs. Then again, it has been suggested that we only know of about 10% of the Theraphosidae in Australia so who knows about the rest....
 

Brettus

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sorry, i didn't mean to imply i thought they had urticating hairs... i have no idea.
Hey, they do not possess urticating hairs. I know that Australia may not be of the "old world" in the historical sense, but as far as I am aware, Aussie T's are members of the Asian selenocosmiae. Asia is after all a stone throne away.

Does anyone know how far back the old world/new world tarantula divide took place in evolutionary terms? I know the fossil record for spiders is scant cos they don't fossilise well, but I was just wondering if the difference between old and new world T's could be explained by the splitting up of Gondwana. Just a random thought?
 

Feathers

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Speculation - the neotarantula

remember that all the land was at one time gathered into one place and it seperated out to form the continents as we have them now. so being seperated that far with differant survival needs may well have adapted to thos differant conditions.
not sure that addressed all your questions but ...
I remember watching a BBC special on dinosaurs; it showed a spider the size of a dog and a pretty formidable one at that - nothing I'd want coming after me. I don't have a clue about Theraphosidae in the fossil record, yet they are a primitive family within the Araneae - I would assume there would have to be a cradle of tarantulas, but what part of Pangea this took place in is pure speculation. I would think we'd be talking convergent evolution, regarding new world Ts, but I could be off track. It's all some pretty interesting food for thought.
 

Becky

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The only one i could shed some light on is...

Why do old world T's hav stronger venom?

I guess its coz they dont possess the urticating hairs that NW's do, so its their only defence. ?
 

ornata

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I remember watching a BBC special on dinosaurs; it showed a spider the size of a dog and a pretty formidable one at that - nothing I'd want coming after me. I don't have a clue about Theraphosidae in the fossil record, yet they are a primitive family within the Araneae - I would assume there would have to be a cradle of tarantulas, but what part of Pangea this took place in is pure speculation. I would think we'd be talking convergent evolution, regarding new world Ts, but I could be off track. It's all some pretty interesting food for thought.
I think we have found fossil record of theraphosidae that is about 40 million years old(rick west)

And the oldest subfamily is ischnocolinae, since it can be found in bought Africa/south europe and America:)

cheers
 

Drachenjager

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I remember watching a BBC special on dinosaurs; it showed a spider the size of a dog and a pretty formidable one at that - nothing I'd want coming after me. I don't have a clue about Theraphosidae in the fossil record, yet they are a primitive family within the Araneae - I would assume there would have to be a cradle of tarantulas, but what part of Pangea this took place in is pure speculation. I would think we'd be talking convergent evolution, regarding new world Ts, but I could be off track. It's all some pretty interesting food for thought.
i think you are referring to megarachne , if so they have rcently decided it was a euryptid not a spider
 

kreuz

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i also have a question concerning the venom.
is the venom of NWs that do not posses urticating hair like holothele, tapinauchenius and psalmopoeus similar to that of OW species. or is it nevertheless weaker?
 

Becky

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I think the venom is pretty potent.. although maybe not quite as potent as Poecilotheria etc...

Interesting question!
 
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