Variations in palynomorph concentrations and relative abundances, including pollen and spores, organic-walled dinoflagellate cysts, and amorphous organic matter (AOM), were studied in sediment core NC Core 2 from the upper slope (1,030 m water depth) of the Nile Cone, southeastern Mediterranean, Egypt. Each sample represents palynomorph deposition for intervals of around 500–1,000 years, and this study provides the first detailed palynological record for the Nile Cone. The dinoflagellate cyst assemblages and AOM production reflect changes in surface water temperature and river discharge in response to climate forcing as marked by variations in pollen and spore indicators of semi-desert vegetation and tropical Monsoon intensity. The basal sediments (approximately 14,600–9,500 yr before present [BP]) contain high concentrations and relative abundances of Polysphaeridium zoharyi, Polysphaeridium spp., Spiniferites elongatus, and Spiniferites spp. during the transition from postglacial to interglacial conditions. Variations in these taxa and total Impagidinium spp. suggest a gradual temperature increase, interrupted by a pre-Holocene cool interval around 11,000 yr BP. The high African monsoon index for this preHolocene time corresponds with pollen evidence of relatively high Nile discharge. The organic-rich S1 sapropel sediments, dated as around 9,500–6,270 yr BP, were deposited several thousand years later, during a time of lower Monsoon index, warmer surface water, and increased dinoflagellate cyst production. This was accompanied by moderate Nile flooding and oxygen-deficient or anoxic bottom water on the upper Nile Cone, mainly supporting the increased production and carbon import hypothesis for eastern Mediterranean S1 formation. Dinoflagellate cyst assemblages in the Nile Cone S1 differ from those of the deeper, more northern Levantine and Cretan basins in the near absence of heterotrophic protoperidinioid cysts, despite the uniformly high organic S1 carbon content. The prevailing climate during the formation of sapropelic sediments in the southeastern Mediterranean was tropical to subtropical, but was interrupted by an early cooler interval with reduced humidity, as marked by re-appearance of Spiniferites elongatus and increased Ephedra pollen. The carbonate-rich surface layers were probably deposited under warm dry climatic conditions with minimum Nile input, but evidence of oxidation prevents detailed interpretation.

Numerous environmental factors as well as oceanic circulation patterns and geographic constraints all contribute to the abundance, distribution, and diversity of present-day marine phytoplankton assemblages. These same factors presumably affected the Paleozoic marine phytoplankton, which was dominated by organic-walled acritarchs and prasinophytes. During the Late Silurian (Gorstian, Ludfordian, and Přídolí) and earliest Devonian (Lochkovian), important paleogeographic, paleooceanographic, and geochemical changes were occurring as well as major compositional changes and diversity fluctuations in the marine organic-walled phytoplankton. Innovative morphologies appeared during the Late Silurian, in both low and high latitude assemblages, but with significant quantitative differences. This was followed by a turnover in assemblage composition during the Silurian/Devonian transition, and an initial radiation of new acritarch and prasinophyte taxa in the Early Devonian.

Observed changes in total phytoplankton diversity during the Gorstian through earliest Lochkovian are based on organic-walled microphytoplankton data derived from published and unpublished key stratigraphic sections where independent age control has been firmly established. These key sections are from: Missouri and Oklahoma, U.S.A. and western Newfoundland, Canada (Laurentia); Gotland, Sweden, and Podolia, Ukraine (Baltica); the Welsh Basin and Borderland (Avalonia); northern France and northern Spain (Armorica); and Libya in northern Africa, and Argentina and Bolivia, South America (Gondwana). Regional biodiversity changes for the organic-walled microphytoplankton were determined for the warm low latitude areas (Baltica, Laurentia, and Avalonia) and temperate to cool higher latitude areas (northern and southern Gondwana).

The Late Silurian—earliest Devonian organic-walled phytoplankton was divided into three major categories to facilitate comparison of compositional fluctuations, both within stratigraphic sections as well as between geographic areas. The three categories, based on overall morphology, are marine chlorophytes and prasinophytes, marine acritarchs, and nonmarine types, including coenobial forms. This triparate grouping is both broad and detailed enough to mark critical changes in both the phytoplankton assemblages, as well as the paleoenvironment. In general, high phytoplankton diversity peaks occurred during the Early and Late Gorstian in the warm low latitude areas, followed by varying fluctuations during the Ludfordian and Přídolí for both the warm low latitude and cool high latitude areas. An initial radiation of new phytoplankton taxa and the appearance of more cosmopolitan assemblages mark the beginning of the Lochkovian.

Dinoflagellate cysts were used as a proxy for reconstructing the salinity variations during the Holocene in the southwestern Black Sea. The aim of this study was to determine the timing of the reconnection between the Black and Marmara seas. Core GeoB 7625-2, located 50 km northeast of the mouth of the Sakarya River, was sampled with a 200-year resolution between 7.42 and 0.52 ka BP. The lower part of the core was sampled with varying resolution. A distinct change in the dinoflagellate cyst assemblages from freshwater/brackish water to saltwater was observed between ∼ 8.25 and ∼ 7.97 ka BP, which is ∼ 0.6 ka earlier than observed in other dinoflagellate cyst studies. This discrepancy may indicate the diachronous salinification of the Black Sea. The freshwater to brackish water assemblage is dominated by Pyxidinopsis psilata and Spiniferites cruciformis, while the most important euryhaline species are Lingulodinium machaerophorum and cysts of Pentapharsodinium dalei. The average process length of Lingulodinium machaerophorum was used as a salinity proxy. Both proxies suggest a gradual reconnection between the Black and Marmara seas, and these findings confirm earlier studies. Peridinium ponticum is restricted to the Black Sea; abundance fluctuations of this species were controlled by salinity variations and changes in nutrient concentrations. Earlier studies have demonstrated that the 800 to 500 year cycles observed in the sedimentary record are related to the intensity of the discharge of the Sakarya River, and linked to the North Atlantic Oscillations. Cysts of Pentapharsodinium dalei and Spiniferites spp. fluctuated synchronously with the clay layer frequency. The poor preservation of these forms may indicate shelfal transport during periods of intense river discharge. The variation in relative abundance of heterotrophic species does not correlate with the clay layer frequency, since upwelling and nutrient supply also influenced their abundances. Lingulodinium machaerophorum shows the highest relative abundances during periods with reduced river input.

Large acritarchs were recovered from the Awaynat Wanin II Formation in the A1-69 borehole, western Libya at 394.4 m. This sample has been dated by acritarchs and spores as Givetian (Middle Devonian). Two species of acanthomorph acritarchs were recovered that are unusually large for the Paleozoic. The first type, represented by a single specimen, is a new occurrence of a previously described but unnamed form from the Middle Devonian of the Sahara. The second type, which is more abundant, is named as Vanguestainidium cucurbitulum gen. et sp. nov. Biogeochemical analysis using infrared microspectroscopy shows that the wall composition of this new taxon is close to algaenans isolated from the green alga Botryococcus braunii Kützing 1849 although these forms are not morphologically similar. The presence of well-preserved fragile palynomorphs, abundant terrestrially-derived palynomorphs including large megaspores, and rare marine palynomorphs suggests deposition in a low-energy nearshore environment such as a coastal swamp.

An Early Devonian (Pragian) plant, Hueberia zhichangensis gen. et sp. nov., is described from the Posongchong Formation, Wenshan district of southern Yunnan, China. It is characterized by stems < 2 mm wide and closely helically-arranged enations. A creeping habit is suggested due to K-type branching. No fertile organs are preserved. Hueberia gen. nov. resembles Drepanophycus and Kaulangiophyton, but is much smaller and has a more regular phyllotaxy.

An organic-walled dinoflagellate cyst, Operculodinium aguinawense sp. nov. is described from recent marine sediments in Biafra Bay, Gulf of Guinea, Atlantic Ocean. This species is characterized by a subspheroidal, egg-shaped cyst body with a fibroreticulate surface wall, and flexible to stout processes with wide, fibrous bases and multifurcate terminations. Paratabulation is only expressed by the loss of a single precingular paraplate (3″). The distribution of this form in recent marine sediments suggests an affinity for lower salinity conditions (29) and as such, it could be an index of paleosalinity changes. Marine palynomorph records from the Gulf of Guinea document its occurrence from at least the Last Interglacial. Fluctuations in abundance appear to be associated with periods of strengthened monsoon dynamics and river discharge.

Paleogene dinoflagellate cysts were recorded from the Chorrillo Chico and Agua Fresca formations at Punta Prat, southern Chile. Due to the presence of Palaeoperidinium pyrophorum, the Chorrillo Chico Formation is no younger than Late Selandian. By comparison with other basins, a Late Danian to Late Selandian age is proposed for the Chorrillo Chico Formation at Punta Prat. The Paleocene—Eocene boundary is characterized by Apectodinium-dominated assemblages in the mid and high latitudes, the Atlantic coast of Isla Grande de Tierra del Fuego in Argentina, and Chile. The absence of this event at Punta Prat suggests a regional hiatus across the Paleocene—Eocene boundary. An Early to Middle Eocene age is assigned to the lower part of the Agua Fresca Formation by comparison with dinoflagellate cyst assemblages from elsewhere in the Southern Hemisphere.

Cotton pollen is thought to exist in the gut of boll weevils for at least 24 hours. Because finding whole or broken cotton pollen grains are valuable clues in determining when boll weevils were living in cotton, the retention of cotton pollen in the gut of the weevil was examined. Boll weevils were fed cotton buds, cotton flowers, and water for five days, then they were placed into cleaned cages without any food. However they were allowed to drink water freely. Weevils were examined at 0, 24, 48, 72, 96, and 120 hours after the buds and flowers were removed. One hundred weevils were dissected at each time interval, and each gut was placed onto a glass slide. Light microscopy was used to determine the presence or absence of cotton pollen. More weevils (63%) at 0 hours contained pollen than weevils at any other interval. Whole pollen grains were not found in weevils after 24 hours. The 120 hour interval contained a single weevil with pollen. In the laboratory test, whole cotton pollen grains indicated that feeding on cotton occurred within 24 hours. When only halves and fragments of pollen were found, cotton feeding occurred 48–120 hours earlier. Additionally, when six or more cotton pollen grains were found in a weevil, it had fed on cotton within 24 hours. This information narrows the boll weevil dispersal times and distances from cotton fields and overwintering areas.

The establishment of the Converrucosisporites confluens Oppel Zone in the Canning Basin of Australia in cored intervals from the Calytrix No. 1 Borehole was considered to be an advance in Gondwana Carboniferous—Permian palynostratigraphy. This was because the zone is associated with a marine fauna that suggests a correlation with the standard Russian Early Permian stages. Moreover the index species has a wide occurrence in Gondwana outside Australia, for example Antarctica, Argentina, Brazil, India, Oman, Saudi Arabia, and Uruguay. The zone was originally considered middle to late Asselian in age, but this was later revised to latest Asselian to Early Sakmarian. Converrucosisporites confluens is reported here from the Ganigobis Shale Member of Namibia in a well-preserved and diverse assemblage including four of the fourteen specified accessory taxa for the Converrucosisporites confluens Oppel Zone. Ash layer IIb of the Ganigobis Shale Member is radiometrically dated as 302.0 ±3.0 Ma (i.e. Pennsylvanian; Gzhelian or Kasimovian) thus the Converrucosisporites confluens Oppel Zone may range earlier than previously thought. Preliminary study of the range top of Converrucosisporites confluens in Argentina and Uruguay suggests that it ranges younger there than in Western Australia with the possibility that the Converrucosisporites confluens Oppel Zone may also be younger than previously thought.

A diverse and well-preserved dinoflagellate cyst and acritarch record, comprising 35 genera and 104 species of dinoflagellate cyst and 14 acritarch taxa, is presented for the Lower Pliocene through Middle Pleistocene (4.00–0.53 Ma) of eastern North Atlantic Deep Sea Drilling Project Hole 610A. The Pliocene samples contain twice as many dinoflagellate cyst taxa than the Quaternary samples but far lower cyst concentrations. The disappearance of taxa during the latest Pliocene is likely to have been associated with global cooling. Eight biozones and four subzones are established, representing a level of detail that surpasses earlier studies. The zones are based mostly on highest occurrences, as these are most prevalent in the Pliocene and Lower Pleistocene. The subzones, based on both the acme and highest persistent occurrence of Habibacysta tectata, appear regionally useful within the Lower Pleistocene. The lowest occurrence of Impagidinium cantabrigiense is a potential marker for the uppermost Gelasian Stage (Lower Pleistocene). While this biozonation is intended primarily for use in the eastern North Atlantic, elements will be applicable across the higher-latitude North Atlantic where calcareous microfossil zonations have reduced reliability and resolution. Most of the stratigraphically useful taxa are illustrated, and selected species are described informally.

The acritarch Ninadiacrodium gen.nov. is erected to include forms with a basically triangular outline, but with a clearly bipolar arrangement of processes. It belongs to the ‘diacrodian’ clade; these are morphotypes with ornament and/or processes at the two opposite poles of the central body. They were extremely abundant and highly diverse during the Late Cambrian and Early Ordovician. The new genus includes the two widely-cited species Ninadiacrodium caudatum (Vanguestaine 1973) comb. nov. and Ninadiacrodium dumontii (Vanguestaine 1973) comb. nov. Both taxa are emended here. Ninadiacrodium is easily recognizable due to its elongate triangular shape, but is clearly differentiated from Veryhachium Deunff 1954, which appears in the Ordovician. Ninadiacrodium is apparently confined to the Late Cambrian, and has a global distribution. It is therefore an index fossil for the Late Cambrian.

A single sample from the Springhill Group of well 2 at La Posesión in the Manantiales oilfield, southern Chile at 1752 m yielded a rich spore-pollen assemblage. The sample is from the base of approximately 32 m of medium- to coarse-grained sandstone with streaks of brown-gray clay and occasional carbonaceous streaks. Forty-nine species of pollen and spores in 36 genera are documented. On the basis of the occurrences of Aequitriradites plicatus, Appendicisporites jansonii, Contignisporites multimuratus, Cyclusphaera sp. A, Muricingulisporis annulatus, and Ornamentifera echinata, the age of the sample is considered to be Early Cretaceous (Hauterivian). The absence of marine palynomorphs indicates that the horizon sampled was deposited in a non-marine setting, close to araucarian and fern vegetation. The spore genus Sphagnites Cookson 1953 is emended, and the species Sphagnum antiquasporites Wilson & Webster 1946 is transferred to Sphagnites.