In spite of the criticisms which have been made on the conclusion that Phoronis is allied to the Pterobranchia, it is thus possible that the view is a sound one, and that the Phoronidea should take their place, with the Enteropneusta and the Pterobranchia, as an order of the Hemichordata.
The Phoronidea (q.v.) are now associated with Hemichordata (q.v.) in the line of vertebrate ancestry, whilst the Chaetognatha (q.v.) remain in solitary isolation.
Brachiopods have been at various times placed with the Mollusca, the Chaetopoda, the Chaetognatha, the Phoronidea, the Polyzoa, the Hemichordata, and the Urochordata.