Annelid worms are segmented worms that have been known to exist for over 500 million years. These worms have long, cylindrical bodies that are divided into segments. They are commonly referred to as earthworms, but they also go by other names. Some of the synonyms for annelid worm include segmented worm, oligochaete, ringed worm, and bristle worm. Oligochaetes are typically found in soil or fresh water, while bristle worms are often marine creatures. The use of these different terms often depends on the context and environment in which the worm is found. Regardless of their name, these worms are important for maintaining soil health and biodiversity in aquatic environments.