Mississippian Discinid Brachiopods Attached to a Soft-bodied Organism

A concretion from the lower Mississippian Meadville Shale Member of the Cuyahoga Formation near Lodi, Ohio, preserves a population of Orbiculoidea newberryi Hall in life position, associated with what is interpreted to be an unidentified soft-bodied organism. The brachipods show a diffuse unimodal orientation, parallel to the axis of the "host" organism, in what was probably an upward direction during the life of the group. Recruitment to the assemblage apparently was periodic. Two size classes, perhaps representing yearly recruitment, contain about equal number of individuals. Most individuals were attached to the soft-bodied organism, but six of the nine smaller specimens were attached to adults of the species. The assemblage is similar to recent discinid assemblages from quiet water and suggests a continuity of basic life style throughout a major part of the fossil record.