MONSTER QUEST: Monster Spiders

History Channel - Original Air Date: October 22, 2008

Do monster spiders up to 5 feet across live in the Amazon, the Congo, or other remote regions of the world?  In 1938, a British couple went to the Congo on a honeymoon safari.  They saw a 4-5 foot creature crossing the road that they at first thought was a big cat or monkey, but then they realized it was a huge spider.  In ancient times, giant sea scorpions got as large as crocodiles, but could huge arachnids still exist?  In the Amazon, a shaman describes a basketball-sized tarantula that could rear up to the height of a man.  In Iraq, US troops report gigantic camel spiders, and in they're know as Texas "deer killers."  How big can such known species grow?  US soldiers claim to have been attacked by cat-sized camel spiders (actually a solifugid).  The one photo of a supposed monster, though, turns out to be two creatures, not one -- though such solifugids have been reported to grow five inches cross.

Despite eyewitness reports, experts doubt that there is enough oxygen in the air today (21%) to support such monsters; air in the age of giant insects had 60% more oxygen.  Bugs have very poor circulatory systems and needed the richer oxygen content to grow to huge size.  In 2007, an enormous web the size of 2 football fields was found in a forest in Texas.  Whether it was created by many spiders working together or by an unknown giant?  Scientists remain unsure.  Field teams turn up no giants, though they find some big tarantulas.  While eyewitnesses can't be discounted, to date there is no solid evidence that monster spiders still exist.