Annelid phylogeny

Annelids are segmented worms, such as earthworms and leeches, belonging to the phylum Annelida. Their phylogeny, or evolutionary history, shows that they share a common ancestor with other invertebrates like mollusks. Annelids are divided into three main groups: Polychaeta (marine worms), Oligochaeta (including earthworms), and Hirudinea (leeches). These segments allow for flexible movement and specialized functions, leading to diverse habitats. Annelids play crucial roles in ecosystems, particularly in soil health, and their study helps scientists understand evolutionary processes among animals.