Probable microvertebrates, vertebrate-like fossils, and weird things from the Wisconsin Ordovician

Phosphatic microfossils including probable microvertebrates occur in the Ea rly and Middle Ordovician rocks of Wisconsin. The eight types described her e include the probable ostracoderm Anatolepis, and six unidentified but pos sible vertebrate fragments as well as the palaeoscolecid worm Milaculum. Th ese fossils are rare, but at two localities several specimens per kg were r ecovered over significant stratigraphic intervals. The high concentration o f certain fossils in the lower part of the Galena Group suggests that there is stratigraphic Value in their description. Identification of similar mat erial or of articulated assemblages of these fossils may eventually lead to identification of biologic affinities.