The calcareous nannoplankton underwent a major diversification between 60 Ma and 61 Ma with the appearance of two important Cenozoic genera, Fasciculithus and Sphenolithus. We have studied the evolution of these genera at four deep-sea sites using a combination of biostratigraphic and assemblage analyses. Our data show that the first appearances of both genera are time transgressive between sites by up to 1 myr, suggesting that these taxa were highly specialized or that ocean environments were heterogeneous. The interval of diversification coincided with a major turnover among nannoplankton assemblages involving an increase in taxa adapted to oligotrophic environments and a decrease in those suited to mesotrophic settings. The opening of niche space for oligotrophs such as Fasciculithus and Sphenolithus coincides with the radiation of oligotrophic planktonic foraminifers, including the genus Morozovella. The appearance of both groups occurred about 1 myr after the recovery of the biologic pump following its collapse at the Cretaceous–Paleocene mass extinction. This suggests that increased export efficiency stripped nutrients from surface waters, causing a major upheaval among marine food webs.

This study tests the fidelity of shallow-water gastropod skeletons as multiproxy archives of paleoenvironmental change by comparing isotopic and trace-metal analyses of specimens of Conus ermineus. Four adult specimens were collected live from Stetson Bank in the northwestern Gulf of Mexico during the summer of 2003. Shells were sampled along axes of growth to produce time-series profiles spanning up to 8 years. δ¹⁸O and Sr/Ca profiles show seasonal cyclicity modified by fast summer and slow winter shell growth. The profiles were combined to estimate paleosalinity. This yields variable results that overestimate salinity range; nevertheless, annual salinity minima and maxima are still evident. The overestimates are attributed to interspecimen Sr/Ca variability and error in the δ¹⁸O_sw-salinity regression. Profiles of δ¹³C show seasonal variation superimposed on a decreasing ontogenetic trend, the latter ascribed to decreasing metabolic efficiency also reflected by an ontogenetic increase in Sr/Ca. Seasonal δ¹³C variation reflects changes in the δ¹³C of dissolved inorganic carbon (δ¹³C_DIC). Salinity and δ¹³C_DIC at Stetson Bank strongly correlate (R² = 0.80, p < 0.0001), and shell δ¹³C minima coincide with local salinity minima following times of peak river discharge. These δ¹³C minima terminate during annual shelf current reversals. Low-salinity waters directly account for less than half the variability in shell δ¹³C but enhance summer stratification and trap respired CO₂ from sediment pore waters. Specimens from this study show mean δ¹³C values 1‰ lower than C. ermineus collected from Stetson Bank in 1971, reflecting the decrease in δ¹³C_DIC from anthropogenic CO₂.

The flora from the Montceau-les-Mines Lagerstätte (Massif Central, France, Late Pennsylvanian) is preserved in small sideritic concretions and was studied in three locations in the (1) Saint-Louis, (2) Saint-François, and (3) Sainte-Hélène opencast mines. Qualitative and quantitative analyses of plant diversity and floristic composition in 6812 nodules indicate substantial variations in the floral composition of these opencast mines. More than 50 taxa are recognized and belong to groups typical of the Late Pennsylvanian flora (lycopsids, sphenopsids, tree ferns, and pteridosperms). Arborescent sphenopsids and tree ferns were the major components at Saint-Louis, whereas the flora from Saint-François consisted mainly of pteridosperms; the one from Sainte-Hélène has a more balanced composition. Taphonomic and sedimentological data show that the flora contained in the nodules was hypoautochthonous to parautochthonous. The Montceau Basin displayed a mosaic of paleoenvironments (e.g., deltaic lacustrine, paludal to fluvial) which favored colonization by plants and animals.

The Glossifungites ichnofacies recognized in Cretaceous strata (Cerro Toro Formation) of the Magallanes foreland basin in southern Chile represents an important discovery in that it extends the stratigraphic utility of firmground trace-fossil suites into thick-bedded, gravity-flow deposits of submarine fan-channel environments. The trace-fossil suite consists of atypically large Diplocraterion, Skolithos, and Arenicolites, which may reach an inferred length of 7 m. The burrows penetrate muddy, matrix-supported conglomeratic deposits dewatered and consolidated as a result of burial and subsequently exhumed by erosive turbidity currents. In a stratigraphic succession dominated by coarse-grained facies >350 m thick, the burrows are abundant at one stratigraphic horizon correlatable up to 200 km². This horizon is interpreted as a stratigraphic discontinuity associated with a long-term cessation of coarse-grained, sediment-laden gravity flows into the basin. The colonized surface is the only marker horizon traceable across much of the Magallanes basin study area.

Studies of phosphatic concretions and associated marine-shelf sediments in the Upper Cretaceous Ripley Formation, central Alabama, demonstrate the positive impacts that early diagenetic mineralization may have on ichnofossil preservation. Distinct ichnofossils are poorly expressed in highly bioturbated, calcareous, organic-rich muds owing to lack of three-dimensional expression, limited contrast between biogenic structures and ambient sediments, and compactional deformation. In contrast, phosphate concretions that formed at shallow sediment depths during early diagenesis exhibit a Cruziana ichnofacies assemblage. This assemblage indicates both (1) incidental preservation, whereby large burrows served as concretion nuclei, and (2) collateral preservation, whereby biogenic structures were incorporated within or on exteriors of concretions as diagenetic fronts migrated outward from body-fossil and other nuclei into surrounding sediments. Although most Ripley Formation ichnofossils were emplaced prior to mineralization, some apparently reflect burrowing that was contemporaneous with and influenced by phosphatization. In either case, concretion growth enhanced ichnofossil visibility by boosting contrast with host sediment, by rendering structures or portions thereof in three dimensions, and by precluding significant compaction. Concretion-hosted ichnofossil assemblages in the Ripley Formation and comparable deposits, analogous to conservation traps in the body-fossil realm, can be regarded as ichnofossil Lagerstätten.

The Kersadiou Formation is well known for its exceptional preservation, diversity, and abundance of mid-Devonian marine fossils. A complete faunal inventory of the Kersadiou Formation over its entire outcrop area is presented here for the first time. Twelve complete sections have been thoroughly sampled from the 28 known outcrops in the Rade de Brest area. The detailed vertical and geographic distribution of 149 identified taxa, coupled with multivariate analyses, allows us to recognize three benthic brachiopod-dominated associations—the Holynetes, Ogorella, and Arcuaminetes associations. These associations reflect a progressive shallowing, which had been previously proposed based on lithological changes from the underlying Quelern Formation to the overlying Tibidy Formation. The corresponding environmental changes are from a protected or restricted marine environment, with a high diversity fauna (Holynetes association), to a shallower, open, higher-energy environment, characterized by a low-diversity assemblage (Arcuaminetes association); the Ogorella association occupies an intermediate position. While the three associations are well developed in the central and eastern parts of the Rade de Brest, only the Arcuaminetes association is well developed in the western outcrop area. This east-west distribution of faunas correlates with the paleoecological gradient evidenced in the studied area.

A new conservation Lagerstätte is described from the middle Pleistocene Shiobara Group of central Japan. The biota includes mammals, birds, amphibians, fish, insects, arachnids, flowers, abundant leaves, fungi, and bacteria preserved within laminites that were deposited in a lacustrine environment. Comminuted plant material in medium-grained, massive sandstones was deposited from high-density flows. This fragmentation of plant material probably indicates that it had decayed prior to transport. Plant and animal remains are largely nonfragmented and were thus transported prior to decay. The laminites are composed of rhythmic, millimeter-scale alternations of clay-to-silt-grade clastics with siliceous, diatom-rich layers. In the western part of the basin the diatoms are preserved as opal-A, but in the eastern part, where soft-part preservation is most common, they have been altered to opal-CT and form thin, white, porcelaneous layers with a lepispheric texture. Soft parts are preserved as carbon residues and microbial films, and although siliceous laminae enclose the fossils, permineralization of tissues is infrequent. Soft-part preservation was promoted by the self-sedimentation of aggregated mats of diatoms that shrouded the biota on the lakebed. This stabilized the carcasses and prevented them from being disturbed. It also prevented the diffusion of both the incoming nutrients and outgoing metabolic by-products between carcasses and surrounding water and may thus have promoted soft-part preservation. Silica cementation also inhibited the destruction of fossils by the intense weathering in the humid Japanese climate.