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Phosphatic microfossils including probable microvertebrates occur in the Early and Middle Ordovician rocks of Wisconsin. The eight types described here include the probable ostracoderm Anatolepis, and six unidentified but possible vertebrate fragments as well as the palaeoscolecid worm Milaculum. These fossils are rare, but at two localities several specimens per kg were recovered over significant stratigraphic intervals. The high concentration of certain fossils in the lower part of the Galena Group suggests that there is stratigraphic value in their description. Identification of similar material or of articulated assemblages of these fossils may eventually lead to identification of biologic affinities.

Phosphatic microfossils including copious microvertebrates and conodont elements indicative of the upperIcriodella discreta–Icriodella deflectaZone (Aeronian) are found in a single bed of the Hendricks Formation, Burnt Bluff Group, Sturgeon Bay, Wisconsin. Scales of thelodonts, includingLoganelliasp. cf.Loganellia sibericaKarajute-Talimaa, 1978, and rareValyalepis cristaTurner (inTurner and Nowlan, 1995) predominate among the microvertebrate remains. Most scales are referred toZuegelepis potanusTurner new genus and species. Associated with the thelodont scales are rare phosphatic fragments of questionable dermal “bone” and scales, possibly of heterostracan origin. Thelodont scales are also found in the Hendricks Formation at Fayette State Park, Michigan and in the subsurface Byron Formation (Burnt Bluff Group) in Schoolcraft County, Michigan.

More than 40 species of siliceous microfossils are present in both T-3 core Fl-437 (Cretaceous) and in core Fl-422 (Eocene) from the central Arctic Ocean. Previous identifications of the silicoflagellates were the basis of the ages for these cores, but diatoms of the two cores, previously unidentified, suggest that Fl-437 could be as old as Campanian rather than middle to late Maastrichtian and that Fl-422 may be early to middle Eocene rather than middle to late Eocene. Identification of archaeomonads and ebridians completes the cataloging of the known biosiliceous assemblages of the older Arctic Ocean.Strong seasonality for the Late Cretaceous and early Cenozoic Arctic Ocean is suggested from alternating layers of vegetative cells and resting spores in both cores. The abundance of fossils is interpreted as evidence for seasonal upwelling in a nutrient-rich and much warmer Arctic Ocean. No evidence of seasonal ice or of ice-rafting is present. The profound climate change from the warmer older Arctic Ocean to the ice-covered condition of the present occurred after deposition of the sediment of Fl-422.

The well-exposed and fossiliferous Permian carbonates in China have yielded Early and Late Permian species of the Sweetognathus complex that permit worldwide stratigraphic evaluation of members of the group. The sporadic appearance of species of Sweetognathus and related genera throughout the Permian in western North America and Iran, in particular, may represent iterative evolution and homeomorphy. The pectiniform element morphologies of the several species are interpreted as most important for evolutionary studies and document a partial Permian biostratigraphy in China that aids in the interpretation of less complete sequences elsewhere. A new genus, Pseudosweetognathus, and four new species, Pseudosweetognathus costatus, Sweetognathus subsymmetricus, S. paraguizhouensis, and Iranognathus nudus, are described.

TheNeogondolella serrata(Clark and Ethington) group was originally reported as a North American provincial conodont lineage. More or less complete Permian sequences now recognized in China include species originally thought to be part of the North American provincial fauna as well as species reported previously from other parts of the world. Comparison of Chinese and North American species may be useful in correlation of series and stage boundaries between the two areas. The Chinese conodont succession demonstrates that most Permian neogondolellids were not provincial but attained worldwide distribution. Late Permian ancestors of Early TriassicNeogondolellaspecies were apparently widespread in the Tethyan Sea and the sudden appearance of TriassicNeogondolellaspecies in North America without Permian ancestors is only the consequence of the absence of the latest Permian marine rocks in North America.Of particular regional stratigraphic interest is the occurrence of the North American speciesN. wilcoxiClark and Behnken in the Chinese late Guadalupian-Dzhulfian. This occurrence supports a late Guadalupian (post-Lamar) age for the uppermost Gerster Formation in Utah.