[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

A number of fossil taxa can be identified as early Lophotrochozoans, even if their precise affinity remains contested.

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.