New specimens of Cyclocystoides scammaphoris (Echinodermata) from the Upper Ordovician rocks of the American midcontinent with implications for cyclocystoid functional morphology Open Access

What lies beneath: geophysical mapping of a concealed Precambrian intrusive complex along the Iowa–Minnesota border Available to Purchase

DOLOMITE FRONTS AND ASSOCIATED ZINC-LEAD MINERALIZATION, USA Available to Purchase

Anatomy of an embayment in an Ordovician epeiric sea, Upper Mississippi Valley, USA Available to Purchase

Geochemical Modeling of ZnS in Biofilms: An Example of Ore Depositional Processes Available to Purchase

Organic-matter source variation and the expression of a late Middle Ordovician carbon isotope excursion Available to Purchase

Taxonomic discussion of the scolecodont genera Nereidavus Grinnell, 1877, and Protarabellites Stauffer, 1933 (Annelida, Polychaeta) Free

Schopfodus, a new conodont genus from the Upper Middle Ordovician of eastern North America Free

Macroscenella (Mollusca) from the Middle Ordovician of Wisconsin; a reinterpretation and reassignment Free

Cupulocrinid crinoids from the Middle Ordovician (Galena Group, Dunleith Formation) of northern Iowa and southern Minnesota Free

Type specimens of the brachiopod Dalmanella? winchelli Cooper, 1956 Free

Lamottia (Favositida, Tabulata) from the Decorah Formation (Kirkfieldian, Ordovician) of Iowa Free

Bryozoan astogeny and evolutionary novelities; their role in the origin and systematics of the Ordovician monticuliporid trepostome genus Peronopora Free

Fracture permeability in folds; an example from the Upper Mississippi Valley zinc-lead district Available to Purchase

Chemical correlation of K-bentonite beds in the Middle Ordovician Decorah Subgroup, upper Mississippi Valley Available to Purchase

Crinoids of the Champlainian (Middle Ordovician) Guttenberg Formation; upper Mississippi Valley region Free

Ordovician calceocrinids from northern Iowa and southern Minnesota Free

Syngenesis versus epigenesis of Mississippi Valley-Appalachian type base metal mineral deposits [discussion and reply] Available to Purchase

Restudy of type species of the Ordovician bryozoan genus Stictoporellina Free

Enargite in the zinc-lead deposits of the upper mississippi valley district Available to Purchase