What is a diagnostic feature of annelida present in earthworm?

A key diagnostic feature of annelids, such as earthworms, is their segmented body structure, which consists of a series of repeating segments called metameres. Each segment contains its own set of muscles and organs, allowing for greater flexibility and movement. Additionally, earthworms possess a coelom, a fluid-filled body cavity that aids in locomotion and organ function. This segmentation is a defining characteristic that distinguishes annelids from other invertebrate phyla.