Megapezia longipes Willard and Cleaves 1930 from the Pennsylvanian Rhode Island Formation of Massachusetts: ichnotaxonomic status

Abstract

The type and only specimen of the ichnospecies Megapezia longipes , from the Pennsylvanian Rhode Island Forma-tion of Plainville, Massachusetts, consists of two poorly defined tracks, one made by a manus and the other by a pes, rather than a single pedal imprint. Whereas the type species of Megapezia , Megapezia pineoi , has tetradactyl pedal imprints, the pes imprint of Megapezia longipes is pentadactyl, a feature that precludes assignment to this ichnogenus. Rather, the tracks share two characteristics with the ichnogenus Matthewichnus , namely elongate digits II and III on the manus, and a pes imprint oriented anterolaterally to the manus imprint, and are thus tentatively reassigned to that ichnogenus. Cf. Matthewichnus longipes is retained as a separate ichnospecies pending the collection of additional ma-terial that can be compared with other species within the ichnogenus. With the tentative reassignment of the Plainville tracks to Matthewichnus , Megapezia becomes monospecific and is no longer recorded in New England. The tracks are the first known occurrence of Matthewichnus from this region.