The muscular axial proboscis is a development for predation and scavenging and characterizes the Phyllodocida of Dales, also recognized by Rouse and Fauchald (1997). Phyllodocida is a large group containing among others, the Acoetidae, Aphroditidae, Eulepethidae, Polynoidae, Chrysopetalidae, Glyceridae, Goniadidae, Paralacyoniidae, Pisionidae, Lactdoniidae, Phyllodocidae, Nephtyidae, Nereididae, Hesionidae, Pilargidae, Sphaerodoridae, and Syllidae. The proboscis in aphroditids, glycerids, nephthyids, phyllodocids and polynoids is similar in having a long cylindrical crushing and, in at least some cases, sucking pharynx made up of concentric lamellae of circular or radial muscle. Strong paired retractor muscles connected to the body wall are not developed; in spite of the extreme length of pharynx, and retraction is effected by longitudinal muscles of oesophagus and buccal tube or by muscles extending on to intestine. In Glycera the muscular pharynx lies well back into the body, but can be everted, to expose the four jaws, without the aid of paired protractor or retractor muscles. A very large Glycera is found in SouthAustralia and is collected commercially (at some risk!) for fishing bait. Nereidids on the other hand, have strong protractor and retractor muscles which are paired and are inserted on the pharynx. Nereidids have a pair of stout jaws associated with the proboscis and in small specimens these are visible through the body wall. the A very common nereidid of the the east Australian littoral zone is Australonereis ehlersi. It tends to burrow in sand in which it constructs a definite sandy tube which can often be seen protruding above the substrate. In the picture shown here the pair of jaws are obscured by the body wall when retracted, though they are clearly visible when everted.

Other Phyllodocida such as Phyllodocidae lack jaws but use their axial proboscis to grasp and suck onto prey so that they can tear pieces off. Eumidia sanguinea and Phyllodoce novohollandiae common on estuarine mudflats along the Australian east coast. Though sand crawlers which can also burrow, they are also capable of swimming. They can detect dead animals from some distance and gather in large numbers.