[6][7] With the introduction of Platytrochozoa and Rouphozoa, one candidate phylogeny is pictured below – though other studies recover a range of alternative possibilities:[8][9][10][11][12][13][14][15] In the most recent research, the three phyla Cycliophora, Entoprocta and Bryozoa makes up a single clade and are the first to branch off from the other lophotrochozoans.

[16][17] Ecdysozoa Gnathifera Gastrotricha Platyhelminthes Mesozoa Cycliophora Echiura Clitellata Siboglinidae Sipuncula Mollusca Brachiopoda Phoronida Entoprocta Ectoprocta Nemertea Another study recovers Lophotrochozoa as equivalent to Platytrochozoa, forming a sister group with Gnathifera at the base of Spiralia.

[18] Ecdysozoa Gnathifera Mollusca Entoprocta Gastrotricha Ectoprocta Phoronida Brachiopoda Annelida Platyhelminthes Nemertea

The clade Lophotrochozoa is named after the two distinct characteristics of its members; the lophophore, a feeding structure consisting of a ciliated crown of tentacles surrounding a mouth, and the developmental stage of the trochophore larva.

Lophophorata such as Brachiozoa and Bryozoa have lophophores, while members of Trochozoa such as molluscs and annelids have trochophore larvae, although some may have none.