Annelida: Master Annelida -explore segmentation

Master Annelida -explore segmentation, classes, examples & quizzes. Ace your biology exam with Vedantu! The phylum Annelida is a group of organisms having ring-shaped segments. The term Annelida is derived from the Latin word; “ Annulus = ring “ There are more than 15000 known species of this phylum. This phylum includes several subgroups based on their identities and anatomical variations. In 1802, Lamarck has first coined the term Annelida for the group of organisms belonging to the taxon vermis. Linnaeus introduced the taxon vermis for the group of worms in 1893. Annelid, any member of a phylum of invertebrate animals that are characterized by the possession of a body cavity (or coelom), movable bristles (or setae), and a body divided into segments by transverse rings, or annulations, from which they take their name. The coelom is reduced in leeches, and Annelida is a phylum of segmented, coelomate, triploblastic animals with organ system level organization. Learn about the different classes of Annelida , such as Polychaeta, Oligochaeta, Hirudinea and Archiannelida, and their features and examples.