These tentacles somewhat resemble the lophophore found in animals like brachiopods and bryozoans , as well as the feeding tentacles of certain chordates . The incompletely known anatomy of pogonophorans was interpreted to show that pogonophorans were chordate relatives. Because pogonophorans live with their lower ends buried in mud, and were broken during the dredging process, it was not until 1964 that a complete pogonophoran was recovered. The forward part of the body, or prosoma , is unsegmented. Because of the segmented opisthosoma, and because pogonophoran larvae have been found to look very much like annelid larvae, pogonophorans are now considered to be close relatives of the annelids, and are classified with them in a larger group, the Trochozoa .
Some nutrition is provided by absorbing nutrients directly from the water with the tentacles.
But most of a pogonophoran's nutrition is provided by symbiotic bacteria living inside the worm, in a specialized organ known as the trophosome that develops from the embryonic gut. The bacteria derive energy from sulfur oxidation, which they use to fix carbon into larger organic molecules, on which the pogonophoran feeds. However, studies on sabelliditid structure have proved inconclusive in determining exactly what these fossils were. Visit this Dutch site on the Five Kingdoms for more info on the Pogonophora . Keep in touch with the Tree of Life for information about the phylogeny and classification of pogonophorans .