Scientists exploring in Brazil's Amazon rain forest have discovered what is believed to be the largest spider ever found...about the size of a small dog and weighing in excess of half a pound.

The South American Goliath Birdeater is the largest spider in the world, but surprisingly, is not deadly to humans. This arachnid has a leg span of  up to 30 cm (about a foot) and can weigh as much as 170 grams - or about as much as a puppy.