A POSSIBLE TRACEMAKER OF ARTHROPHYCUS

A single organic compression of a long-bodied arthropod was collected from the Silurian (Llandovery) Tuscarora Formation at Mann Narrows, Pennsylvania. The preserved portion includes two tagmata: the anterior tagma has broad, rectangular pleurae each of which corresponds to two segments in the trunk, indicating diplosegments; the posterior tagma has monosegments with long, gently curving, posterior facing lateral ‘spines’. Head and appendages are not preserved. The compression fossil occurs in shale which is interbedded with sandstones containing Arthrophycus, an hypichnial trace that is abundant throughout the Tuscarora Formation in central Pennsylvania. The morphology of the arthropod matches the general proposed morphology of the producer of Arthrophycus, making the Tuscarora specimen a possible tracemaker. The closest affinities of the arthropod appear to lie with the problematic Oxyuropoda from the Devonian of Ireland.