Which group does not belong to the phylum Annelida?

The group that does not belong to the phylum Annelida is Rotifers. Annelids, such as leeches, earthworms, and segmented worms, are characterized by their segmented bodies and a coelom that is divided by septa, which is a defining feature of the phylum.

Rotifers, on the other hand, are part of the phylum Rotifera and are known for their small size and unique wheel-like structures of cilia that they use for feeding and locomotion. They have a completely different body organization, lacking true segmentation and a coelom, which distinguishes them from annelids. Understanding these distinctions helps clarify the taxonomical relationships among different groups of organisms within the animal kingdom.