Fossil dinoflagellate cysts of the Paleogene peridiniacean subfamily Wetzelielloideae have a stable tabulation pattern similar to that of other fossil peridiniaceans, but distinguished by a four-sided (quadra) rather than a six-sided (hexa) 2a plate. Aside from tabulation, wetzelielloideans show great morphological variability, especially in ornamentation and horn development, but also in wall structure. This diversity has distracted attention from the morphological variation of the archeopyle, which, although always formed through loss of the 2a plate only, shows variations that we consider critical in unravelling the group's phylogeny. Important factors are the shape and relative dimensions of the archeopyle and whether the operculum is attached (adnate) or detached. These parameters allow us to define five archeopyle types: equiepeliform, hyperepeliform, hypersoleiform, latiepeliform and soleiform. Based primarily on archeopyle type and secondarily on wall morphology and ornamentation, we recognise six genera with an equiepeliform archeopyle, four with a hyperepeliform archeopyle, five with a latiepeliform archeopyle, five with a soleiform archeopyle and one with a hypersoleiform archeopyle. The earliest known wetzelielloideans, which occur around the Paleocene—Eocene boundary, have an equiepeliform archeopyle. Other archeopyle types evolved rapidly: taxa with hyperepeliform, latiepeliform and hypersoleiform types are known from the Ypresian. Latiepeliform and hyperepeliform types are restricted to the Ypresian and Lutetian. Forms with the soleiform archeopyle appeared in the late Lutetian, but were rare until the Bartonian, when they became the dominant type, and they were the only type in Priabonian and younger strata. Wetzelielloideans became extinct in the middle Oligocene. We make numerous taxonomic proposals, including the following new genera: Castellodinium, Dolichodinium, Epelidinium, Kledodinium, Michouxdinium, Petalodinium, Piladinium, Rhadinodinium, Sagenodinium, Sophismatia, Stenodinium, Stichodinium and Vallodinium. We emend the diagnoses of Charlesdowniea, Dracodinium and Wilsonidium, and erect the species Kledodinium filosum, Petalodinium sheppeyense and Sagenodinium franciscanum.

Palynomorphs undergo progressive darkening and loss of translucency as temperature increases over geological time periods. The use of oxidising agents that lighten highly mature palynomorphs enables their observation and documentation using transmitted light microscopes, but in certain cases, oxidation destroys part of or the entire organic residue. A new method was tested using palynological residues derived from Devonian and Carboniferous metasediments that allows the microscopic observation and documentation of highly mature palynomorphs without loss of specimens. In its simplest form, it uses non-oxidized, air-dried 20-µm-sieved palynological residues mounted on acrylic slides without the use of cover slips. Observation and documentation were performed routinely using reflected light petrographic microscopes. The resulting photomicrographs are scanning electron micrograph (SEM)-like in the sense that the observed objects are opaque. Depth-of-field issues can be easily overcome by editing the partially focussed images with z-stack image software. The method was found to be useful up to estimated peak rock temperatures of 290°C and over a wide range of tectonic deformation degrees. The application of this method may allow the biostratigraphic and paleaeoenvironmental study of metasediments in areas where this kind of information was assumed to be unattainable.

The last ca. 4100 cal yr BP of palaeoenviromental conditions in the Llanganates National Park, central Ecuadorian Andes, has been reconstructed from the pollen record ‘Anteojos Valley’ (3984 m elevation). The pollen record, dated with four radiocarbon dates, indicates that the local páramo vegetation was relatively stable with only minor fluctuations since the mid-Holocene. The páramo vegetation was characterised mainly by Asteraceae, Cyperaceae and Poaceae. The regional lower mountain rainforest vegetation is mainly represented by Moraceae/Urticaceae, and the upper mountain rainforest by Melastomataceae, Polylepis and Weinmannia. Between ca. 4100 to 2100 cal yr BP, páramo was the main vegetation type with a low presence of mountain rainforest, probably reflecting cool conditions. Between ca. 2100 cal yr BP and the present, the proportion of páramo vegetation increased with a decreased occurrence of mountain rainforest, suggesting cooler and moister conditions. Low frequencies of fires were evidenced since the mid-Holocene. However, there is a slight increase of regional fire between ca. 4100 and 3100 cal yr BP. The low abundance of larger carbonised particles since the beginning of the record suggests a low occurrence of local fire in the study area.

The Cañadón Asfalto Formation, Cañadón Asfalto Basin, Patagonia, Argentina, is interpreted as fluvial-lacustrine deposits. A palynological study of the lower and middle parts of the unit, at the Cañadón Lahuincó and Cañadón Caracoles sections, Cerro Cóndor Depocentre Chubut province, northwestern Patagonia, Argentina is presented. The quantitative composition of the palynofloras is characterised by the dominance of pollen produced by the conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites and Callialasporites), suggesting that warm-temperate and relatively humid conditions under highly seasonal climate prevailed during the depositional times of the unit. The abundance of Botryococcus supports the presence of a shallow lake with probably saline conditions. Five palynomorph ecogroups (PEGs) were recognised: upland, lowland, riverside, coastal lake and aquatic. The ecological requirements of the different plant families forming the PEGs enable the inference of a sub-tropical palaeoclimate for the Cañadón Asfalto region during late Early Jurassic to mid Middle Jurassic, which is consistent with the ‘seasonally dry (winterwet)‘ biome.

The first online modern organic-walled dinoflagellate cyst determination key has been launched at  www.marum.de/dinocystkey.html. This key is based on easily recognisable morphological features of dinoflagellate cysts that can be observed using standard transmitted light microscopy. To date, the key includes 96 cyst species that can be found in late Quaternary marine sediments. This key is free of charge to users, and will be continuously updated and improved by the authors. For each individual species of dinoflagellate cyst, the website provides information on its defining morphological characteristics and the cyst—motile stage relationship. It gives a comparison with other morphologically similar taxa, links to publications with original cyst descriptions and outlines their modern global distribution where this information is available. All species descriptions are illustrated by line drawings showing their most distinctive characteristics, and accompanied by high-quality bright-field photomicrographs. The key is compatible with all major computing platforms (including smartphones) and software.

Palynologists interested in better understanding the sedimentation and energy of depositional environments have often included studies of palynomaceral fragments, particularly when performing palynofacies analyses. Due to the difficult nature of classifying these fragments, researchers have developed numerous, often overlapping, classification schemes. These different schemes make it difficult to compare and contrast between research projects. Determining the appropriate scheme to apply when counting these fragments can be confusing, and application of these schemes can yield inconclusive results, especially when sedimentation and energy are in constant flux. A scheme of five categories, including brown wood (palynomaceral 1–2), leaf cuticle (palynomaceral 3), black debris (palynomaceral 4), structureless organic matter (SOM) and resin, is utilised here. It is applied to the analysis of 64 modern samples from the top 0–4 cm of sediment collected throughout the Gulf of Papua, Papua New Guinea. These samples span a suite of common marine depositional environments: river mouths and deltas, the proximal portion of the continental shelf dominated by a large clinoform, and turbidite and hemipelagic/pelagic deposits on the slope and in the deep ocean basin. Principal component analysis (PCA) confirms this simplified classification scheme provides an indirect means of assessing distance from shore and shelf-slope break, overall water depth and sediment accumulation rate, but other factors, such as processing technique, marine productivity, sediment source, time in transport and residence and bioturbation, are taken into account to fully explain distribution.