In the 50's we went camping in southeastern Utah. On the way to 4 corners, we camped by a river. I found a huge rollie pollie that was curled up. I picked it up and rolled it around in my hand. I then picked it up by the sides between my thumb and forefinger. To my shock it opened up and bright lime green legs, pinchers, and a stinger tail unfolded. I dropped it and watched it disappear into the brush. I have never seen that species in any book. Any ideas?

At a guess, it was possibly a bark scorpion that had recently eaten something high in copper salts. They come in just about all colors, from nearly translucent to almost black, depending on diet. Rich Ayrey in Arizona is fairly knowledgeable about the species in that area. Here's a page from his website about bark scorpions: <i>Centruroides sculpturatus</i> Ewing, 1928