Paleobiology of a three-dimensionally preserved paropsonemid from the Devonian of New York

摘要

A three-dimensionally preserved stellate fossil from the Middle-Upper Devonian of New York is described. Although it shares gross similarities with oral cones of anomalocaridids, we interpret it as the mold of the dorsal portion of the segmented alimentary canal of the rare, soft-bodied animal Paropsonema cryptophya. Together with two other dorsally preserved P. cryptophya specimens, such fossils strengthen the hypothesized link between two primitive deuterostome stem groups - the paropsonemids and the eldonids. Although the taxonomic affinities of these groups remain uncertain, it is important to illustrate fossils like these because they provide paleontologists with a 'search image' for more material that may elucidate patterns in early animal evolution or may help revise taxonomic interpretations. The new specimen of Paropsonema is also the youngest described occurrence of the paropsonemids and its sediment-filled gut is consistent with an epibenthic lifestyle for that group.