일반명 : 다모류(Worm Polychaeta)
학 명 : Pieckonia helenae
지질시대 : 후기석탄기(Pennsylvanian (~300 m.y.a.)
지 층 : Mazon Creek, Pit 11,
원산지 : 미국(Francis Creek shale, Braidwood, Illinois)

The Polychaeta (Bristleworms) have a diverse representation among Mazon Creek fossils. The segmented bodies of the Polychaeta have paired lobes called parapodia that have a function in locomotion or respiration. The parapodia have numerous bristles that are the source of the name of the class (Polychaeta means many bristles). This one is thought to have been a predatory species, as are many modern-day bristleworms, due to the fact that some have been found with the remains of Ostacods in the gut. This fossil worm comes from an old collection that has the field collector’s inventory number.