Extrusive igneous rocks erupt onto the surface, where they cool down quickly to form crystals. There are some that cool down so quickly that they form an amorphous glass. Basalt, granite, obsidian, and pumice are some examples of this.
The main difference between coelomates and pseudocoelomates is the coelomates possess that is included, a ‘true’ coelom as their body cavity whereas pseudocoelomates possess a ‘false’ coelom.
