Definition: The word "Archaeostomata" refers to a group of animals that are known for their ability to build large, multi-layered structures like caves or buildings. These creatures were originally found on Mars and later colonized Earth as well. Definition: An Archaeostomata is an animal that has the ability to construct large, multi-level structures such as coves or buildings through their burrowing into the earth. They are known from both Mars and other planets in our solar system.