pogonophoran science definition

Any of various wormlike marine invertebrates of the phylum Pogonophora that grow in upright chitin tubes, usually at great depths. Pogonophorans have tentacles that are often featherlike and are attached to the head region. An intestine is present in the embryonic stage but disappears as the animal matures. Pogonophorans are preserved in the fossil record as early as the Cambrian Period, and are thought to be related to chaetognaths, hemichordates, and echinoderms.