anonguy Posted December 19, 2012 #1 Share Posted December 19, 2012 Could spiders like these still exist ? Do you think what they saw was actually a spider? Other than the testimonies of natives, the fullest account by Westerners appears in a cryptozoological book by George Eberhart. On page 204, Eberhart relates the terrifying experience of an English couple traveling through a jungle region of what is now called the Congo: "R.K. Lloyd and his wife were motoring in the Belgium Congo in 1938 when they saw a large object crossing the trail in front of them. At first, they thought it was a cat or monkey, but they soon realized it was a spider with legs [spanning] nearly 3 feet [across]." Link to comment Share on other sites More sharing options...
skookum Posted December 19, 2012 #2 Share Posted December 19, 2012 I think it has been proved impossible with the current oxygen levels on the planet. I am not sure if any spiders were that large in the past either. 4 Link to comment Share on other sites More sharing options...
Hasina Posted December 19, 2012 #3 Share Posted December 19, 2012 Book lungs keep them small. 2 Link to comment Share on other sites More sharing options...
Cynical Sounds Posted December 19, 2012 #4 Share Posted December 19, 2012 Yep impossible. Spiders dont have lungs and absorb all there oxygen through an area on there abdomen called a book lung. http://en.wikipedia.org/wiki/Book_lung Basically a spider that size wouldn't be able to get enough oxygen to internal tissue that far from its book lungs and it cells would become oxygen starved and die. 1 Link to comment Share on other sites More sharing options...
King Fluffs Posted December 19, 2012 #5 Share Posted December 19, 2012 Their circulation system currently stops them from growing to epic proportions due to the planets oxygen level. I'm not quite sure if they posses an open or closed system, my biology's a little rusty. Link to comment Share on other sites More sharing options...
Simbi Laveau Posted December 19, 2012 #6 Share Posted December 19, 2012 Ahh,yes common sense may say no,but there's stuff in the Congo ,yet to be documented . Especially insects .Who knows . Hagrid would heartily disagree as well . Link to comment Share on other sites More sharing options...
Insanity Posted December 19, 2012 #7 Share Posted December 19, 2012 I believe they have a closed circulatory system, and the heart may or may not be segmented. Some molluscs have an open circulatory system. Some scorpions and spiders do have a copper-based pigment, called hemocyanin, that as a similar function to haemoglobin. Seems the species that have this are those in cold, low oxygen pressure environments, where haemogoblin is not efficient. It is not bound to blood cells, and thus is suspended in the blood fluid. The limitation on size is more due to transporting dissolved oxygen throughout the body if I recall correctly. They would need a circulatory system that also transport oxygen throughout, such as what vertebrates have, to reach larger sizes. 2 Link to comment Share on other sites More sharing options...
TheLastLazyGun Posted December 19, 2012 #8 Share Posted December 19, 2012 (edited) Famous English naturalist and cryptozoologist, William J. Gibbons, has hunted for what some think may be a living African dinosaur called Mokele-mbembe. On his third expedition in search of the creature he came upon natives who related their experiences with giant spiders. He explained his experience: "On this third expedition to Equatorial Africa, I took the opportunity to inquire if the pygmies knew of such a giant spider, and indeed they did! They speak of the Jba Fofi, which is a "giant" or "great spider." They described a spider that is generally brown in colour with a purple abdomen. They grow to quite an enormous size with a leg span of at least five feet. The giant arachnids weave together a lair made of leaves similar in shape to a traditional pygmy hut, and spin a circular web (said to be very strong) between two trees with a strand stretched across a game trail." "These giant ground-dwelling spiders prey on the diminutive forest antelope, birds, and other small game, and are said to be extremely dangerous, not to mention highly venomous. The spiders are said to lay white, peanut-sized eggs in a cluster, and the pygmies give them a wide berth when encountered, but have killed them in the past. The giant spiders were once very common but are now a rare sight." The fact of the matter is that scientists estimate that there are five million species of life on this planet that are yet to be discovered. It is entirely possible that one day someone will capture the giant Jba Fofi spider and have it recognised by science. Edited December 19, 2012 by TheLastLazyGun Link to comment Share on other sites More sharing options...
PlanB Posted December 20, 2012 #9 Share Posted December 20, 2012 In my opinion, all spiders are much too large for my taste. However, I have an uneasy truce with the ones in my house. I don't smash them on sight, and they're allowed to eat all of the bugs they can catch and promise not to walk all over my face while I'm sleeping. 2 Link to comment Share on other sites More sharing options...
Q-C Posted December 20, 2012 #10 Share Posted December 20, 2012 Yup, that darn anatomy will do it every time. Spiders run in bursts for a reason. And as far as a tarantula, they are way too heavy-bodied to grow to this size and still move efficiently and effectively. T. blondi weighs in at 1/4 lbs easy! Link to comment Share on other sites More sharing options...
PlanB Posted December 20, 2012 #11 Share Posted December 20, 2012 And as far as a tarantula, they are way too heavy-bodied to grow to this size and still move efficiently and effectively. T. blondi weighs in at 1/4 lbs easy! Good lord, that would make a terrifying hamburger patty! 1 Link to comment Share on other sites More sharing options...
ReaperS_ParadoX Posted December 20, 2012 #12 Share Posted December 20, 2012 (edited) Famous English naturalist and cryptozoologist, William J. Gibbons, has hunted for what some think may be a living African dinosaur called Mokele-mbembe. On his third expedition in search of the creature he came upon natives who related their experiences with giant spiders. He explained his experience: "On this third expedition to Equatorial Africa, I took the opportunity to inquire if the pygmies knew of such a giant spider, and indeed they did! They speak of the Jba Fofi, which is a "giant" or "great spider." They described a spider that is generally brown in colour with a purple abdomen. They grow to quite an enormous size with a leg span of at least five feet. The giant arachnids weave together a lair made of leaves similar in shape to a traditional pygmy hut, and spin a circular web (said to be very strong) between two trees with a strand stretched across a game trail." "These giant ground-dwelling spiders prey on the diminutive forest antelope, birds, and other small game, and are said to be extremely dangerous, not to mention highly venomous. The spiders are said to lay white, peanut-sized eggs in a cluster, and the pygmies give them a wide berth when encountered, but have killed them in the past. The giant spiders were once very common but are now a rare sight." The fact of the matter is that scientists estimate that there are five million species of life on this planet that are yet to be discovered. It is entirely possible that one day someone will capture the giant Jba Fofi spider and have it recognised by science. geeez a spider with five feet leg span thats huge! Can you imagine what something like that would eat Theres no way the book lungs could maybe grow bigger with the spider? Edited December 20, 2012 by R4z3rsPar4d0x Link to comment Share on other sites More sharing options...
PlanB Posted December 20, 2012 #13 Share Posted December 20, 2012 In addition to having an ineffecient respiratory and circulatory system for such a size, giant spiders would also have to tackle the problem of having to support their girth with just a relatively flimsy exoskeleton. Apparently, in addition to more atmospheric oxygen, there was also less gravity in prehistoric times allowing insects and arachnids to grow larger. I wonder if instead of a giant spider, people could be spotting some sort of terrestrial crab. Coconut crabs can have legspans of up to 3 feet and have much thicker exoskeletons to support their weight. They also like to do spidery things like climb trees and freak people out. (see attached pic) Problem is, they're pretty slow and clumsy compared to the nimble spider. But who knows, if there's any creature with enough disdain for nature to break it's rules, it's the spider. Many species have evolved remarkable adaptations. There are species that fish, those that live entirely underwater, those that build trapdoors with intricate trip wires. I just learned from this site that there's one that builds decoys of itself using spider silk. Maybe somewhere out there, there's one that found a way to evolve freakishly, unjustifyingly large. Link to comment Share on other sites More sharing options...
Insanity Posted December 20, 2012 #14 Share Posted December 20, 2012 geeez a spider with five feet leg span thats huge! Can you imagine what something like that would eat Theres no way the book lungs could maybe grow bigger with the spider? I believe the challenge is not the actual size of the book lungs to the spider, but how oxygen gets diffused into the body. At the larger sizes the ratio of the book lung volume compared to body volume (Lung/Body) is too low to permit enough oxygen to diffuse throughout the body, and organs/tissues do not receive enough. The book lung would have to scale up more then the body, and at the larger sizes may potentially take up most of the body. In the movie "Mimic" it was pointed out that this was one anatomical change in the Judas Bug was the development of lungs, enabling them to grow to human size. In addition to having an ineffecient respiratory and circulatory system for such a size, giant spiders would also have to tackle the problem of having to support their girth with just a relatively flimsy exoskeleton. Apparently, in addition to more atmospheric oxygen, there was also less gravity in prehistoric times allowing insects and arachnids to grow larger. I wonder if instead of a giant spider, people could be spotting some sort of terrestrial crab. Coconut crabs can have legspans of up to 3 feet and have much thicker exoskeletons to support their weight. They also like to do spidery things like climb trees and freak people out. (see attached pic) Problem is, they're pretty slow and clumsy compared to the nimble spider. But who knows, if there's any creature with enough disdain for nature to break it's rules, it's the spider. Many species have evolved remarkable adaptations. There are species that fish, those that live entirely underwater, those that build trapdoors with intricate trip wires. I just learned from this site that there's one that builds decoys of itself using spider silk. Maybe somewhere out there, there's one that found a way to evolve freakishly, unjustifyingly large. Lesser gravity was not the reason for larger insects and other arthropods, as Earth's gravity has remained mostly constant. In those times though it is largely believe the oxygen content of Earth's atmosphere was higher. Currently it is about 21% of the atmosphere, and may have been 50% more, or ~40%, hundreds of millions of years ago. This alone would allow them to grow larger as the external oxygen content was higher, thus diffusing more into their bodies without any extra effort. Link to comment Share on other sites More sharing options...
PersonFromPorlock Posted December 20, 2012 #15 Share Posted December 20, 2012 OK, we're all agreed it couldn't be a giant spider. That doesn't rule out something spiderish evolved from spiders with changes that let it be that size, or something non-spiderish that just looks like a giant spider. The point is that 'It couldn't be!' is a non-responsive response to 'We saw it.' The real question is 'Did they see what they said they saw? If so, what was it?' Link to comment Share on other sites More sharing options...
PlanB Posted December 20, 2012 #16 Share Posted December 20, 2012 Lesser gravity was not the reason for larger insects and other arthropods, as Earth's gravity has remained mostly constant. In those times though it is largely believe the oxygen content of Earth's atmosphere was higher. Currently it is about 21% of the atmosphere, and may have been 50% more, or ~40%, hundreds of millions of years ago. This alone would allow them to grow larger as the external oxygen content was higher, thus diffusing more into their bodies without any extra effort. Ah, well thanks for clearing that up. My understanding was that an older earth had reduced gravity and that combined with the oxygen content accounted for the larger arthropods. Link to comment Share on other sites More sharing options...
Insanity Posted December 20, 2012 #17 Share Posted December 20, 2012 It could not have been a giant spider in regards to what we understand about spider anatomy, physiology and how how we classify species. If it was something physically similar to a spider, but perhaps possessed lungs to permit the larger sizes, it really would not be a spider, and would likely be classified differently. I am not certain if the exoskeleton weight or strength is the real limiting factor in their sizes, but their respiratory and circulatory most likely are. Change those to match that of a terrestrial vertebrate, you could have a very larger spider roaming around looking for dogs to eat. That would be a significant change in physiology for arthropods though. Link to comment Share on other sites More sharing options...
Insanity Posted December 20, 2012 #18 Share Posted December 20, 2012 Ah, well thanks for clearing that up. My understanding was that an older earth had reduced gravity and that combined with the oxygen content accounted for the larger arthropods. The gravitational field of an object is related to its mass and radius, and while those of the Earth's may have changed somewhat over the millions of years, probably not significantly enough to account for a noticeable change. Link to comment Share on other sites More sharing options...
Q-C Posted December 20, 2012 #19 Share Posted December 20, 2012 And arthropods today grow larger when put in oxygen rich environments. But not science fiction size. Link to comment Share on other sites More sharing options...
Boribel Posted December 20, 2012 #20 Share Posted December 20, 2012 (edited) This one is big. [media=] [/media] Edited December 20, 2012 by Boribel 2 Link to comment Share on other sites More sharing options...
Q-C Posted December 20, 2012 #21 Share Posted December 20, 2012 (edited) gotta know how to handle them, it is not hard to tick off either T. blondi or T. sturmi! Both often confused with each other even in the hobby. And tarantulas are so vulnerable if they fall, due to their anatomy as well. So handling is not something to take lightly. Edited December 20, 2012 by QuiteContrary Link to comment Share on other sites More sharing options...
Orcseeker Posted December 21, 2012 #22 Share Posted December 21, 2012 Even during the times of a higher percentage of oxygen, spiders didn't reach as epic proportions as insects like the dragonfly or millipede did. The Goliath bird eating spider, correct me if I'm wrong, is the largest to have ever existed. Given our oxygen levels are a lot lower, let alone in those conditions spiders not being overly huge let alone anywhere near the size of these ones in the Congo pretty much highlights the fact that this may just simply be one of those "mysterious Congo" stories. Link to comment Share on other sites More sharing options...
JGirl Posted December 21, 2012 #23 Share Posted December 21, 2012 (edited) if i saw a giant spider my first inclination would be to hop on its back and ride that puppy! Edited December 21, 2012 by JGirl 1 Link to comment Share on other sites More sharing options...
PlanB Posted December 21, 2012 #24 Share Posted December 21, 2012 Even during the times of a higher percentage of oxygen, spiders didn't reach as epic proportions as insects like the dragonfly or millipede did. The Goliath bird eating spider, correct me if I'm wrong, is the largest to have ever existed. Given our oxygen levels are a lot lower, let alone in those conditions spiders not being overly huge let alone anywhere near the size of these ones in the Congo pretty much highlights the fact that this may just simply be one of those "mysterious Congo" stories. You may be right. Goliath bird eaters are probably the biggest in terms of girth, but I think the huntsman slightly beats it in terms of leg span. A fossil thought to be the biggest spider ever discovered and called megarachne ended up being that of a sea scorpion. A possible contender to the goliath bird eater is another South American tarantula called a chicken eating spider that was recently discovered. So far, no condor-eating spiders. Link to comment Share on other sites More sharing options...
ReaperS_ParadoX Posted December 21, 2012 #25 Share Posted December 21, 2012 Can someone post a picture of the Bird eating spider? Id like to see how big they get Link to comment Share on other sites More sharing options...
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