New high-resolution microfossil record from a clay succession in the US Gulf Coastal Plain reveal more accurate age estimates for the critical Eocene–Oligocene transition (EOT), a global climate event marked by the rapid expansion of the first permanent Antarctic ice sheet 34 million years ago. These data suggest a coeval major increase in sedimentation rate. Future isotopic and palaeoecological work on this core can be more precisely integrated with other global records of the EOT.

Changes in morphology during development can have profound impacts on an organism but are hard to quantify as we lack preservation in the fossil record. As they grow by adding chambers, planktic foraminifera are an ideal group to study changes in growth in development. We analyse four different species of Jurassic foraminifers using a micro-CT scanner. The low morphological variability suggests that strong constraints, described in the modern ocean, were already acting on Jurassic specimens.

We used organic-walled microfossils to better define the Plio–Pleistocene transition (2.56 Ma) that is associated with the intensification of the Northern Hemisphere glaciation. The disappearance of species around 2.75 Ma reflects an ecological response accompanying the Greenland ice sheet growth. A strong regionalism marks the Labrador Sea and suggests cooler conditions than elsewhere in the North Atlantic, although our zone boundaries are contemporaneous with the eastern North Atlantic.

To better understand radiolarian evolution and taxonomy, two middle Cambrian specimens recovered from Australia were studied using micro-CT. Analyses of their 3-D models revealed for the first time their skeletal architecture constructed of spicules. Insertion of an artificial sphere into their shells indicates that they may have secreted their spicules one by one during cell enlargement. The timing of skeletal genesis may be an important factor influencing the morphology of early radiolarians.

Diatom assemblages in seasonally sea-ice-covered areas of the Sea of Okhotsk, a marginal sea of the western North Pacific, were investigated. We have selected diatom taxa relating to sea-ice coverage by comparing diatom assemblages in sea-ice, sinking-particle, and surface-sediment samples. The results of the study provide fundamental information for the reconstruction of past sea-ice cover based on ice-algal diatoms in sediments in the Sea of Okhotsk and the North Pacific.

Three well-preserved new species of Middle Jurassic (Bajocian) planktonic foraminifera from the continental margin of northwest Australia are described. This is on the southern shelf of the Tethys Ocean, and these planktonics are the first to be reported from the Jurassic Southern Hemisphere. Described as new are Globuligerina bathoniana australiana n. ssp., G. altissapertura n. sp. and Mermaidogerina loopae n. gen. n. sp. The research is part of a study of regional Jurassic foraminifera.

We identify the first continuous carbonate-bearing sediment record from the tropical ocean that spans the entirety of the global warming event, the Middle Eocene Climatic Optimum, ca. 40 Ma. We determine significant mismatches between middle Eocene calcareous microfossil datums from the tropical Pacific Ocean and established low-latitude zonation schemes. We highlight the potential of ODP Site 865 for future investigations into environmental and biotic changes throughout the early Paleogene.

We described two new species of the fossil dinoflagellate cyst genus Svalbardella. S. clausii sp. nov. has a narrow range in the lowermost Chattian and may be related to cooler surface waters. S. kareniae sp. nov. ranges from Lower Oligocene to Lower Miocene and favours more open marine conditions. Our study illustrates the close phylogenetic relationship between Svalbardella and Palaeocystodinium and shows that surface ornamentation and the tabulation are variable features within both genera.

This paper describes a new species of the genus Desmocysta from the Late Cretaceous in the Norwegian Sea. The short stratigraphic range for this new species makes it a good biostratigraphic marker. The available published data also indicate that this genus is restricted to higher latitudes in the Northern Hemisphere and is suggested to have preferred turbid waters and stressed marine environments.

We compared three methods of breaking apart well-cemented carbonate rocks in order to obtain liberated fossiliferous material. The first two methods are traditional and the third is novel to this field. The novel technique (fragmentation using electric pulses, SELFRAG) proved to be the most efficient and effective at liberating microfossil material from surrounding rock. We suggest best practice for using this technique and further materials in which it could prove successful in future.

Foraminifera are marine microorganisms with a calcium carbonate shell. Their fossil remains build up on the seafloor, forming kilometres of sediment over time. From analysis of the foraminiferal record we can estimate past climate conditions and the geological history of the Earth. We have developed an artificial intelligence system for automatically identifying foraminifera species, replacing the time-consuming manual approach and thus helping to make these analyses more efficient and accurate.

The microfossils from a Cretaceous outcrop in southern Turkey are described and used to interpret the age of the rocks and their depositional setting and how sea level has changed. These results are compared both locally and regionally, identifying broad correspondence with regional sea level events. A new species of microfossil is described, confirming that many microfossils of Arabia are localised in their distribution.

During the early Toarcian (Jurassic, 180 Ma) a hyperthermal event, the Jenkyns Event, occurred, affecting the oxygenation of the sea bottom. The integrated study of foraminiferal and ostracod assemblages with geochemical proxies allows us to interpret the incidence of this event in the Western Tethys, more exactly in the South Iberian Palaeomargin. Diminution of diversity, changes in abundance, and opportunist vs. specialist are coincident with the event.