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In Coal Creek Canyon, Utah, the Spring Canyon Member of the Blackhawk Formation is divisible into four regressive hemicycles of deposition, each representing the downdip part of a nearshore-to-offshore sequence. The first and fourth hemicycles are best developed. Individual bedding units span middle-shoreface to lower-offshore lithofacies, the latter corresponding to a thin intertongue of Mancos Shale.Trace fossil assemblages include ~22 ichnospecies and 17 ichnogenera: Ancorichnus, Aulichnites, Chondrites, Cylindrichnus, Ophiomorpha, Palaeophycus, Phoebichnus, Planolites, Rosselia, Schaubcylindrichnus, Scolicia, Skolithos, Taenidium, Teichichnus, Terebellina, Thalassinoides, and Uchirites. Diversity and abundance of ichnospecies are greater in nearshore than in offshore lithofacies. Distal deposits are typified by obscure bioturbate textures: Cylindrichnus concentricus, Palaeophycus heberti, and Rosselia socialis are prevalent through the remainder of the lithofacies suite. Ophiomorpha irregulaire and Schaubcylindrichnus coronus are most common in middle-shoreface beds and Chondrites ichnosp. in upper-offshore beds; Ophiomorpha nodosa and O. annulata also are common in this part of the sequence.

Extensive silicified faunules of Middle and Late Ordovician sphinctozoan sponges have been assembled from the northern part of the eastern Klamath Mountains in northern California. The sponges are from eugeosynclinal rocks that are the westernmost Middle Ordovician to Late Devonian rocks at that latitude in North America. Seventeen new species occur in the assemblages, including 10 porate and 7 aporate forms. New genera of porate forms are Amblysiphonelloides and Corymbospongia, and new porate species include: Amblysiphonella grossa, Amblysiphonelloides tubula, A. reticulata, Imperatoria mega, I. media, I. minima, I. irregularis, Corymbospongia adnata, C. mica, and C.(?) perforata. These are the first reported occurrences of Amblysiphonella and Imperatoria in the Ordovician. New aporate genera are Cystothalamiella and Porefieldia, and new aporate species include: Cystothalamiella ducta, C. craticula, C. tuboides, Porefieldia robusta, Girtyocoelia epiporata, and G. canna. This is the oldest known occurrence of Girtyocoelia, which is generally considered a Late Paleozoic form. Cliefdenella obconica n. sp. is characterized by an obconical growth form in contrast to other species of the genus that are more massive or explanate. Cliefdenella is considered here as an imperforate sphinctozoan.Minor isolated hexactines and hexactine-derived spicules of Hexactinellida were associated with the sphinctozoans. No particular taxa within the class can be distinguished from these individual elements.

The genus Bimuria Ulrich and Cooper, 1942, is a biogeographically important member of middle and late Ordovician brachiopod faunas of the Callahan–Gazelle area in the eastern Klamath Mountains of northern California. In middle Ordovician deposits the genus is widespread and ranges from Nevada in the west to southwestern Siberia in the east; however, in late Ordovician beds it was previously known only in Sweden and Northern Ireland. In addition to the northern California occurrence reported here, new late Ordovician occurrences are also noted in east-central Alaska–Yukon Territory and Northwest Territories. Three species of Bimuria are described, including the new species, B. californiensis.A preliminary survey of species described in the literature suggests that the ratio of the length of the dorsal adductor field to the length of the elongate area in the brachial valve decreases from middle to late Ordovician species, and thus may be of biostratigraphic value.