Ok to displace some previous theories and such.
First to start with the main point of screaming, sorry spiders can't "scream" in the sense of how we might do. They lack vocal cords and so can not
expel air from the lungs to make any sound. Even if it were possible then it would server no purpose since all spiders are deaf, having no ear
There have been comments of things such as Wolf spider "song" however this is caused by the spiders rubbing legs and pedipalps to create a rythmic
huming. This is used for a number of reasons as all spiders are hypersensitive to vibrations.
So sorry but you didnt hear it scream, most probable thing i could think of is air. By this i mean the same thing as lobster screams when boiled,
it's a known fact that it is just air escaping at high velocities, and was most likely the same thing as your shoe hit it fast enough and at a
correct angle to force the air out.
Ok to move onto banana spiders, sorry but they aint super dangerous spiders (at least not the one your showing in the pictures), the ones shown are
not even "hunting" species, they make and live in webs waiting for prey to come to them. Their bite is not dangerous unless one is alergic. (much
like bees and wasps)
There is however a very dangerous spider that is sometimes called a Banana spider, it's other names include Wandering spider for one, and it is
probably in the top 5-6 of deadly species. It gained its Banana name from getting itself into banan boats bound for the US from South America, and
looks very different from the web dwelling banana shaped spider.
Incase that aint enough do a google for the Brazilian wandering "banana" spider Phoneutria fera
and the harmless Banan spider, sometimes
called Golden silk spider Nephila clavipes.
To address the camel spider, well sorry but most of the coming out from the linked sites comments is way way off. If lucky they may hit 5" and
possibly 10mph tops. They're not true spiders as someone stated already, nor do the possess any venom. So those stories of being eaten without
feeling is untrue, as is the thing about camel stomachs.
Solpugids are found worldwide also not just in iraq, including around 50 types in southwest US. They get their common name by their colour nothing
more. They are fairly aggressive as spiders go, but not to the extent of attacking humans. If your a small bug or beetle then watch out!! otherwise
just let them get off you or out of your way and your fine.
The most likely cause for any ill effects from bite from these creatures has been put down to infection of the wound, since they do have pretty big
Hope that clears up any specualtion.
[edit on 12-9-2004 by feygan]