This note presents the first stratigraphic, paleoenvironmental, and systematic account of Silurian foraminifers in Wisconsin, which include nine previously described species of Ammodiscus, Glomospirella, Hemisphaerammina, Hyperammina, Lagenammina, Psammosphaera, Stomasphaera, Thurammina, and Webbinelloidea (Appendix 1). Early Silurian carbonates in this area (Fig. 1) were deposited in shelf and ramp environments in the western part of the Michigan Basin (Harris et al., 1998), and the foraminifers are associated with macrofaunal communities that represent Benthic Assemblages BA3 to BA5 of Brett et al. (1993).
Silicified agglutinated foraminifers were obtained from acidinsoluble residues processed for conodonts, sponge spicules, and macrofauna (Watkins et al., 1994; Kuglitsch, 1996; Watkins and Kuglitsch, 1997; Watkins and Coorough 1997a, 1997b). Silicification of the specimens, rather than a composition of agglutinated siliceous grains, is indicated by lack of detrital silica in enclosing dolostones, variable detail of preservation, and association with other silicified fossils.