An iguana is a rain forest animal and a bearded dragon is a desert animal, they require different temperatures, humidity, food, and overall space. A bearded dragon needs a certain amount of space, too much space and it will get stressed or not bask properly, an iguana needs a much larger space because it's a larger animal.
There's the risk of parasites. Your iguana may carry a parasite that doesn't affect the iguana, but may affect the bearded dragon, same with your bearded dragon.
Stress and fighting could also kill one of them as well.
Because they are not in an area that is in danger of having an earthquake
"Article 1 of The United States Constitution established the legislative branch of the federal government, the United States Congress.The Congress is a bicameral legislature of a House of Representative and a Senate."
