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For assessment of the potential of the Beppu Bay sediments as a Global boundary Stratotype Section and Point (GSSP) candidate for the Anthropocene, we have integrated datasets of 99 proxies. The datasets for the sequences date back 100 years for most proxy records and 1300 years for several records. The cumulative number of occurrences of the anthropogenic fingerprint reveal unprecedented increases above the base of the 1953 flood layer at 64.6 cm (1953 CE), which coincides with an initial increase in global fallout of 239Pu+240Pu. The onset of the proliferation of anthropogenic fingerprints was followed by diverse human-associated events, including a rapid increase in percent modern 14C in anchovy scales, changes in nitrogen and carbon cycling as recorded by anchovy δ15N and δ13C, elevated pollution of heavy metals, increased deposition of novel materials (spheroidal carbonaceous particles, microplastics, polychlorinated biphenyls), the occurrence of hypoxia (Re/Mo ratio) and eutrophication (biogenic opal, TOC, TN, diatoms, chlorophyll a), unprecedented microplankton community changes (compositions of carotenoids, diatoms, dinoflagellates), abnormally high spring air temperatures as inferred from diatom fossils, and lithological changes. These lines of evidence indicate that the base of the 1953 layer is the best GSSP level candidate in the stratigraphy at this site.

Although the life cycle of Margalefidinium polykrikoides, formerly called Cochlodinium polykrikoides, has been described previously, the descriptions on asexual and sexual phases of this species collected from Korean coastal waters are strange and still unclear. We collected the resting cysts of M. polykrikoides from surface sediments and re-examined the germination process, and asexual and sexual life stages, and the mating behavior of the vegetative cells using a microscope equipped with high-resolution time-lapse digital camera. The resting cyst of M. polykrikoides had a distinct germination process; before germination, a mature cell in shape was visible within the resting cyst body, and the cell quickly emerged from the resting cyst. The asexual reproduction and cell chain formation of M. polykrikoides were generated in a slightly oblique direction at the epicone of cell and the chain-forming cells of M. polykrikoides could form the chain-forming temporary cysts without asexual or sexual reproduction. The planozygote produced by gamete fusion of M. polykrikoides may not necessarily develop to resting cysts but instead may divide into vegetative cells occasionally. In this phase, the armored cell, which was previously recorded by Kim et al. (2007), was not observed. The sexuality of M. polykrikoides had a homothallic mating behavior.

Gonyaulax verior was initially described as Amylax diacantha from Belgian coastal waters a century ago but its detailed morphology needed restudy. Here, we established nine strains of G. verior by germinating cysts or isolating cells from localities from the European Atlantic to the Caspian Sea and the Pacific Ocean. Both cyst and thecal morphology were examined by light and scanning electron microscopy. SSU, LSU and/or ITS-5.8S rRNA gene sequences were obtained from all strains. Cells of G. verior have a plate formula of Po, 4′, 2a, 6-7′′, 6C, 6S, 6′′′, 1p, 1′′′′ with an L-type ventral organisation, characterised by two either straight or curved antapical horns of variable length. Cysts of G. verior are oval, smooth and contain one or two yellow accumulation bodies. The maximum-likelihood and Bayesian inference analyses based on SSU and LSU rRNA gene sequences revealed two clades of G. verior, referred to as ribotypes A and B. Genetic distances based on ITS-5.8S rRNA gene sequences within the same ribotype were less than 0.06, but greater than 0.32 between ribotypes. G. verior is reclassified as Sourniaea diacantha gen. et comb. nov., which is attributed to Lingulodiniaceae together with Pyxidinopsis, Lingulodinium and Amylax. Our results suggest that Lingulodiniaceae can be separated from Protoceratiaceae and Gonyaulacaceae based on ventral organisation, apical complex, ventral pore and number of anterior intercalary plates. One strain of S. diacantha was examined for yessotoxin production by LC-MS/MS but did not produce toxin.

Severe damages will result in human society, when several different critical natural phenomena coincide. One example relates to the resting cysts of Alexandrium species (dinoflagellates that cause paralytic shellfish poisoning), which are preserved in surface sediments throughout Osaka Bay, Japan. These cysts have been found to accumulate particularly densely in shallow areas in the inner parts of Osaka Bay, where a tsunami caused by an earthquake could occur any time. Damage by a tsunami could cause a change of the coastal ecosystems at Osaka Bay including the resuspension of surface sediments containing resting Alexandrium tamarense cysts and the subsequent redistribution of the cysts in newly deposited sediment. Under certain environmental conditions, these cysts could germinate and form dense blooms, leading to paralytic shellfish poisoning. Such a scenario could also affect other coastal areas, including the southern coast of the Korean Peninsula.

In the seasonally hypoxic semi-enclosed Omura Bay, Japan, regression equations estimating year-round nutrient [NO3 + NO2, NH4, PO4, Si(OH)4] concentrations in pore water were successfully constructed based on water temperature and the concentration of biogenic elements in surface sediments, except for NH4 and PO4 concentrations in summer when the hypoxic water mass develops. Core incubation studies revealed that pore water NH4 and PO4 concentrations under anaerobic conditions increased 1.4–2.2 and 1.8–2.1 times, respectively, above levels estimated with the regression equations. These were in good agreement with the values observed in the field during summer. The gradient in nutrient concentrations between the measured values in the overlying water column and the estimated values in the pore water revealed that spatial fluctuations in nutrient fluxes at the sediment–water interface across the Omura Bay ranged from 1.5 to 2 times, reaching up to 3–4 times in the summer. Annual nutrient fluxes from the sediment (690–780 ton-N year−1 for DIN, 77–85 ton-P year−1 for DIP, and c.a. 4700 ton-Si year−1 for DSi) were comparable to those from terrestrial areas. Accurate estimation of internal loadings is essential to properly evaluate residual nutrients and organic matter in the water column and their effect on aquatic ecosystems.

Despite the fact that dinoflagellate cysts of the diverse genus Spiniferites are abundant in coastal and estuarine sediments worldwide, little is known about patterns of their seasonal or annual pr...

Harmful algal blooms (HABs) caused by an unknown dinoflagellate species have frequently occurred in the Pearl River Estuary, China Since 2006. These blooms were associated with severe water discoloration and economic losses, ranging from several km2 to 300 km2 with the maximum recorded cell density being 2.77 × 107 cells⋅L−1. This unknown dinoflagellate species was initially identified as Cochlodinium geminatum and subsequently reclassified as Polykrikos geminatus. However, after reviewing the original descriptions for Cochlodinium geminatum sensu Schutt (1895) and the genus Polykrikos, we considered this species is incongruent with their original descriptions. Further morphological examinations and particularly phylogenetic analyses based on the SSU and partial LSU rRNA genes of isolates and resting cysts from China and Japan prompted us to consider it a new species of a new genus. This new species was proposed to be Pseudocochlodinium profundisulcus gen. et sp. nov., based on its open comma-shaped apical structure complex (ASC), cingulum encircling the cell less than one and a half turns, a deep sulcus with a torsion of a half turn, either single cell or cell chain consisting of two cells with the same number of nuclei and zooids, the resting cyst bearing lobed ornaments, and the evolutionary distances from Polykrikos (and others) on the phylogenetic trees constructed using the concatenated SSU and partial LSU rRNA gene sequences. Metabarcoding investigation of surface sediment samples collected in China revealed that the species to be widely present along the entire Chinese coast with the highest abundance in the South China Sea. Further re-analysis of the Tara Oceans metabarcoding dataset targeting the SSU rRNA gene V9 domain suggested a global distribution of this new genus. Phylogenetic analyses on 46 OTUs (average length: ∼552 bases) of its LSU rRNA gene sequences (mainly D1-D2 domains) obtained from surface sediment samples revealed intraspecific genetic diversity of this species. Interestingly, based on the different distributions and the abundance of these OTUs along the coast of China, this species appeared to have expanded its distribution from the South China Sea to the northern Yellow Sea, or preferred a warm water habitat. We consider that the present work improves the taxonomy and provides important insights into the biogeography of Pseudocochlodinium profundisulcus.⋅

8 pages, 2 tables, A recently published study analyzed the phylogenetic relationship between the genera Centrodinium and Alexandrium, confirming an earlier publication showing the genus Alexandrium as paraphyletic. This most recent manuscript retained the genus Alexandrium, introduced a new genus Episemicolon, resurrected two genera, Gessnerium and Protogonyaulax, and stated that: “The polyphyly [sic] of Alexandrium is solved with the split into four genera”. However, these reintroduced taxa were not based on monophyletic groups. Therefore this work, if accepted, would result in replacing a single paraphyletic taxon with several non-monophyletic ones. The morphological data presented for genus characterization also do not convincingly support taxa delimitations. The combination of weak molecular phylogenetics and the lack of diagnostic traits (i.e., autapomorphies) render the applicability of the concept of limited use. The proposal to split the genus Alexandrium on the basis of our current knowledge is rejected herein. The aim here is not to present an alternative analysis and revision, but to maintain Alexandrium. A better constructed and more phylogenetically accurate revision can and should wait until more complete evidence becomes available and there is a strong reason to revise the genus Alexandrium. The reasons are explained in detail by a review of the available molecular and morphological data for species of the genera Alexandrium and Centrodinium. In addition, cyst morphology and chemotaxonomy are discussed, and the need for integrative taxonomy is highlighted, Support to DMA from the NOAA ECOHAB program (Grant #NA15NOS4780181) is gratefully acknowledged. Support to EG, AR, NS from the COPAs project (CTM2017-86121-R) is acknowledged. IGL and CJBS are COFFA-IPN and EDI-IPN fellows, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Dinoflagellates are a major component of the modern plankton. Of the 2192 species of marine free-living dinoflagellates presently described, an increasing number are being shown to produce resting cysts (probably hypnozygotes) within their life cycle. With rare exception, only the resting cysts fossilize, so they are of central importance in tracing the history of dinoflagellates through geological time. Cysts of many of the more common dinoflagellate species have distinctive morphologies allowing their geographic and stratigraphic occurrences to be traced. An ever-increasing number of taxa are also being shown to produce distinctive and geologically preservable cysts, potentially enhancing our knowledge of the diverse representation of dinoflagellates through time. Here the organic-walled cysts of 73 rare, poorly known or morphologically problematic marine dinoflagellate cyst species belonging to the orders Gymnodiniales (nine species) and Peridiniales (64 species) are reviewed, described and illustrated, and their stratigraphic ranges assessed. The names Echinidinium aculeatum and Echinidinium transparantum are validated herein. © 2019 Elsevier B.V.

The taxonomy of the dinoflagellate cyst-based genus Votadinium has been in need of revision. This was accomplished here by integrating morphology, LSU rDNA sequences, and cyst wall composition analyses through micro-Fourier transform infrared spectroscopy. Three new species, Votadinium pontifossatum, V. rhomboideum and V. reidii, were described as cyst stages of Protoperidinium paraoblongum, P. quadrioblongum, and P. steidingerae, respectively. A previously undescribed type of ornamentation was reported for V. pontifossatum. A fourth new species was assigned to V. concavum. Furthermore, Lejeunecysta psilodora Benedek (=Lejeunecysta psuchra Matsuoka), was re-described as V. psilodora and the holotype re-illustrated, as was done for the holotype of V. spinosum Reid. New illustrations were provided for V. elongatum and V. nanhaiense. LSU rDNA sequences of V. concavum revealed its placement in the Oceanica section of the genus Protoperidinium, supporting earlier evidence that the Oceanica section and the cyst based genus Votadinium form a monophyletic clade. Thus, Votadinium could be considered the cyst equivalent of the motile-defined Oceanica section. The cyst walls of Votadinium spinosum, V. calvum and V. pontifossatum are built from carbohydrate-based macromolecules with N-containing functional groups in agreement with the heterotrophic nature of their motile stage. Comparison with related genera Trinovantedinium and Quinquecuspis reveals that the species and genera can be separated based on cyst wall composition, supporting the phylogeny based on molecular data and/or ecological differences. Furthermore, Trinovantedinium applanatum spectra unexpectedly show an additional absorption at 1510 cm−1 indicating an aromatic group that is commonly reported for sporopollenin and not seen in dinoflagellate cysts so far. This study stabilizes the taxonomy of the cyst genus Votadinium, clarifies its relationship to the Oceanica section of Protoperidinium, and further supports the application of whole cyst wall chemistry in helping address problems in dinoflagellate cyst taxonomy and ecology.

The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / 3F Seminar room, National Institute of Polar Research

Mangrove forests and adjacent creeks are known to be highly productive estuaries, which are partly supported by benthic microalgae that grow on the sediments. During surveys investigating the microalgal floras of mangrove swamps in the eastern part of Java Island, a mud sample unexpectedly included large numbers of a notorious fish killer, Chattonella-like motile cells, and its resting cysts. These motile cells were established as clonal cultures for further identification and physiological tests. The cysts were examined through palynological and molecular biological means. Identification based on light microscopy and ribosomal RNA gene sequences confirmed that these cells and cysts were Chattonella marina var. marina. While the strains were genetically identical to the temperate strains isolated from Japan and China, temperature experiments showed that the Indonesian strains possessed a high maximum quantum yield of photosystem II even after exposure to 34 °C, a temperature at which the Japanese strain could not survive. Salinity experiments showed adaptation of the strains to a salinity of 15. These findings, together with the discovery of populations of cysts in the mangrove sediment, highlight the tough and unique nature of the Indonesian strains, which are likely adapted to wide fluctuations of temperature and salinity in mangrove swamps, and pose a potential risk to fisheries in Indonesia.

Shellfish aquaculture in Ofunato Bay, Northeast Japan, was seriously damaged by a tsunami generated by the Great East Japan Earthquake, March 11th, 2011, accompanied by paralytic shellfish poisoning (PSP) outbreaks caused by Alexandrium tamarense (Dinophyceae). To understand longer future trends of PSP, an investigation was made of the historical occurrence and causes of Alexandrium outbreaks after the tsunami. Vertical distributions of Alexandrium cysts in two sediment-cores from Ofunato Bay revealed that the sediments above ca. 25 cm were eroded, re-suspended and re-deposited, and they included unusually abundant Alexandrium cysts. This abundance of cysts was due to re-deposition of older sediments by the tsunami. The first Ofunato Bay PSP incident was in 1961 after the Chilean Earthquake tsunami and was probably caused by similar unusual blooms of Alexandrium germinated from older sediments as the Great East Japan tsunami, together with nutrient enrichment because of population increase at the start of shellfish aquaculture., Marine Environmental Research, 135, pp.123-135; 2018

We investigate the cyst-theca relationship of Impagidinium caspienense. Through an incubation experiment, we succeeded in examining the motile stage. Additional molecular analysis of single-cyst PCR (LSU and SSU rDNA) reveal that the cyst is related to the species Gonyaulax baltica Ellegaard et al. (2002). The ability of this species to belong to two types of cyst-based genera (spiniferate and impagidinioid) suggests that environmental (particularly salinity) and not genetic factors explain the formation of both morphotypes by Gonyaulax baltica, which provides evidence for heterospory in this species. The affiliation to Gonyaulax baltica demonstrates that Impagidinium caspienense is not endemic to the Caspian Sea. The phylogenetic position of several other gonyaulacoid species is also documented: Impagidinium pallidum, Ataxiodinium choane, Pyxidinopsis psilata, Spiniferites belerius, and Spiniferites ramosus. The LSU and SSU rDNA based phylogenies suggest that the genera Impagidinium and Spiniferites are not monophyletic, and that Pyxidinopsis psilata and Ataxiodinium choane are close to Gonyaulax verior and Gonyaulax polygramma, respectively. In addition, this study accentuates the importance of cyst morphology in the classification of the Gonyaulacales. This article is protected by copyright. All rights reserved.

Myanmar is tenth among the world’s fish-producing countries and third in ASEAN (Association of Southeast Asian Nations). To understand the mechanisms underlying the high production, oceanographic and phytoplankton surveys, including primary productivity measurements based on pulse amplitude modulation fluorometry, were conducted near an active fishing ground near Myeik City. Three surveys, one in each of the representative seasons and covering the characteristic coastal environments, showed well-defined seasonality in primary production and phytoplankton occurrence. End of the dry season was the most productive, with productivity of 2.59 ± 1.56 g C m−2 day−1 and high concentration of chlorophyll a (3.14 ± 2.64 µg L−1). In this season, the phytoplankton population was dominated by high densities of the diatoms Bellerochea horologicalis and Chaetoceros curvisetus, whereas primary productivity was low at the onset of the dry season, 1.36 ± 0.77 g C m−2 day−1. However, this low primary production might be compensated by activation of microbial food chains originating from high dissolved organic carbon. The rainy season exhibited the lowest production, 6.6% of the end of the dry season, due to the extensive discharge of turbid water from the rivers which lowered euphotic layer depth and resulted in an unusually high diffuse attenuation coefficient of 2.30 ± 1.03 m−1. This incident of turbid water may be related to soil erosion from deforestation and mangrove deterioration. This research reveals the seasonal trend in Myanmar’s coastal productivity and its relationship to the tropical monsoon climate as well as emphasizing the importance of tropical coastal environments to the sustainability of the fisheries.

We aimed to clarify and quantify the abundance of palynomorphs of tropical coastal marine shallow-water sediments collected from Oman, Malaysia, Okinawa and also the Sanriku region of Japan for making a comparison with temperate areas. Palynomorphs in these samples contained phototrophic and heterotrophic dinoflagellate cysts, acritarchs, resting cells of Prasinophyceae and Chrysophyceae, tintinnomorphs, microforaminiferal linings, testate amoebae and resting eggs and body fragments of copepods. The sediment samples from Malaysia, Oman, and Okinawa were characterized by dominance of heterotrophic marine palynomorphs, in particular microforaminiferal linings and heterotrophic dinoflagellate cysts, while the samples from Sanriku were different and dominated by phototrophic and heterotrophic dinoflagellate cysts. In addition subtropical-tropical assemblages were characterized by low cell/grain concentrations, especially phototrophic dinoflagellate cysts. These characteristics of marine palynomorphs...

Although the genus Pseliodinium within the family Ceratoperidiniaceae includes Ceratoperidinium falcatum, Cochlodinium cf. convolutum, C. cf. helix and unidentified Cochlodinium species, it is in need of reclassification because of the morphological differences and lack of morphological details of the species within the genus. A Cochlodinium-like species was isolated from a Korean coastal area and examined by light and scanning electron microscopy, as well as by the analysis of nuclear-encoded small subunit (SSU) and large subunit (LSU) rDNA. The Korean isolate was morphologically characterized by cellular torsion, and outer rows consisting of small rectangular and polygonal vesicles were visible along the sides of the cingulum. The apical structure complex (ASC) formed a complete circle surrounding the cell apex, consisting of three parallel rows of vesicles. In the ASC, the upper row was sometimes hidden and very small knobs were present on the central row. Morphological characteristics separated the Korean isolate from Ce. margalefii, Pseliodinium fusus(=Ce. falcatum), Kirithra asteri and Gymnodinium species (Gymnodinium sp. 1 and sp. 2) within the family Ceratoperidiniaceae. However, the morphological characteristics coincided with those of the previously recorded C. convolutum, C. cf. helix and other Cochlodinium species within the same family. Phylogeny based on SSU and LSU rDNA sequences revealed that the Korean isolate forms a clade independent from P. fusus, although they have high sequence similarity. Based on the morphological and phylogenetic analyses, we propose the new genus Torquentidium gen. nov. and a new combination for C. cf. helix and the Korean isolate Torquentidium convolutum erected within the family Ceratoperidiniaceae.

In Japanese Sign Language (JSL), as well as in many other sign languages, wh-final sentences are common, which is not the case of spoken languages. This paper is an attempt to explain how wh-final constructions in JSL are derived under the generative approach. We considered the basic distributions of the wh-element in wh-final constructions including the wh-double (i.e. wh-in situ and wh-final) construction, and argue that previous approaches to wh-finals in other sign languages, such as Cecchetto et al. (2009) and Petronio and Lillo-Martin (1997), cannot be directly applied to JSL wh-finals. We propose that the wh-word with the non-manual marker for the wh-interrogative (wh-NMM) is split into two segments; the wh-NMM as a wh-interrogative marker and the wh-word as a wh-operator. Following Cable (2010), we assume that the wh-NMM functions as a Q-particle and moves to Focus[+Q]0. Under this proposal, splitting of the wh-element and movement of each segment take place in the wh-double construction. While the clause-final wh-word occupies the head position with the [+Q] feature realized as the wh-NMM, the wh-word accompanied by the wh-NMM can be moved from its original position to the clause-initial position by wh-operator movement. In either case, the wh-NMM must co-occur with the wh-word, since the wh-NMM needs to be morphologically supported.

We establish the cyst-theca relationship of the dinoflagellate cyst species Trinovantedinium pallidifulvum Matsuoka 1987 based on germination experiments of specimens isolated from the Gulf of Mexico. We show that the motile stage is a new species, designated as Protoperidinium louisianensis. We also determine its phylogenetic position based on single-cell polymerase chain reaction (PCR) of a single cell germinated from the Gulf of Mexico cysts. To further refine the phylogeny, we determined the large subunit (LSU) sequence through single-cell PCR of the cyst Selenopemphix undulata isolated from Brentwood Bay (Saanich Inlet, BC, Canada). The phylogeny shows that P. louisianensis is closest to P. shanghaiense, the motile stage of T. applanatum, and is consistent with the monophyly of the genus Trinovantedinium. Selenopemphix undulata belongs to a different clade than Selenopemphix quanta (alleged cyst of P. conicum), suggesting that the genus Selenopemphix is polyphyletic. Trinovantedinium pallidifulvum is widely distributed with occurrences in the Gulf of Mexico, the North Atlantic, the northeast Pacific and southeast Asia. In addition, we illustrate the two other extant species, Trinovantedinium applanatum and Trinovantedinium variabile, and two morphotypes of Trinovantedinium. Geochemical analyses of the cyst wall of T. pallidifulvum indicate the presence of amide groups in agreement with other heterotrophic dinoflagellate species, although the cyst wall of T. pallidifulvum also includes some unique features.

Species belonging to the dinophyte genus Scrippsiella are frequently reported in marine waters, but information on their distribution in brackish environments is limited. Here we describe a new species, S. plana, through incubation of non-calcified cysts from sediments collected in the South China Sea and Caspian Sea. The vegetative cells consist of a conical epitheca and a rounded hypotheca with the plate formula of Po, X, 4′, 3a, 7′′, 5C+t, 5S, 5′′′, 2′′′′. It differs from other Scrippsiella species by its flattened body in dorsoventral view and a small first anterior intercalary (1a) plate (half the size of plate 3a). Scrippsiella plana strains from the South China Sea and Caspian Sea share identical internal transcribed spacer (ITS) sequences, and show phenotypic plasticity and local adaptation in growth rate at various salinities, consistent with the environments in which they originated. In addition, two strains of S. spinifera were obtained by incubating ellipsoid cysts with calcareous spin...

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established. Here, a new species, Halodinium verrucatum sp. nov., is described and molecular evidence (single specimen SSU and LSU rDNA sequencing) reveals that both this new species and Hexasterias problematica, collected from sediment samples in the Skagerrak and Baltic Sea, are resting stages of prorodontid ciliates. Additionally, infrared spectroscopic analysis (micro-FTIR) of Hexasterias problematica and Halodinium spp. specimens indicates a carbohydrate-based composition of the cyst wall with evidence for nitrogen-containing functional groups. A similar composition is recorded for tintinnid loricae, which further supports the placement of Hexasterias and Halodinium as ciliate cysts, and the composition is consistent with the heterotrophic nature of ciliates. The morphologically similar species Radiosperma corbiferum has a comparable composition, suggesting a similar ciliate affinity and indicating the utility of micro-FTIR in understanding acritarch affinity. Hexasterias problematica typically occurs in coastal waters from temperate to arctic regions. Halodinium verrucatum sp. nov. is observed in temperate estuarine sediments in the northern hemisphere.

We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 Evitt WR. 1963. A discussion and proposals concerning fossil dinoflagellates, hystrichospheres, and acritarchs, I. National Academy of Sciences, Washington, Proceedings. 49(2):158–164.[Crossref], [PubMed], [Web of Science ®], , [Google Scholar] and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 Sarjeant WAS. 1970. The genus Spiniferites Mantell, 1850 (Dinophyceae). Grana. 10(1):74–78.[Taylor & Francis Online], , [Google Scholar] occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al. 1973 Wall D, Dale B, Harada K. 1973. Descriptions of new fossil dinoflagellates from the Late Quaternary of the Black Sea. Micropaleontology. 19(1):18–31.[Crossref], , [Google Scholar]) Londeix et al. 2009 Londeix L, Herreyre Y, Turon J-L, Fletcher W. 2009. Last Glacial to Holocene hydrology of the Marmara Sea inferred from a dinoflagellate cyst record. Rev Palaeobot Palynol. 158(1-2):52–71.[Crossref], [Web of Science ®], , [Google Scholar], Spiniferites? rubinus (Rossignol 1962 Rossignol M. 1962. Analyse pollinique de sédiments marins quaternaires en Israël II. - Sédiments pleistocènes. Pollen et Spores. 4:121–148. [Google Scholar] ex Rossignol 1964 Rossignol M. 1964. Hystrichosphères du Quaternaire en Méditerranée orientale, dans les sédiments Pléistocènes et les boues marines actuelles. Revue de Micropaléontologie. 7:83–99. [Google Scholar]) Sarjeant 1970 Sarjeant WAS. 1970. The genus Spiniferites Mantell, 1850 (Dinophyceae). Grana. 10(1):74–78.[Taylor & Francis Online], , [Google Scholar], and Thalassiphora balcanica Balteş 1971. This summary forms the basis for a set of papers that follows, where points raised during the workshops are explored in greater detail.

Strains of a dinoflagellate from the Salton Sea, previously identified as Protoceratium reticulatum and yessotoxin producing, have been reexamined morphologically and genetically and Pentaplacodinium saltonense n. gen. et sp. is erected to accommodate this species. Pentaplacodinium saltonense differs from Protoceratium reticulatum (Claparède et Lachmann 1859) Bütschli 1885 in the number of precingular plates (five vs. six), cingular displacement (two widths vs. one), and distinct cyst morphology. Incubation experiments (excystment and encystment) show that the resting cyst of Pentaplacodinium saltonense is morphologically most similar to the cyst-defined species Operculodinium israelianum (Rossignol, 1962) Wall (1967) and O. psilatum Wall (1967). Collections of comparative material from around the globe (including Protoceratium reticulatum and the genus Ceratocorys) and single cell PCR were used to clarify molecular phylogenies. Variable regions in the LSU (three new sequences), SSU (12 new sequences) and intergenic ITS 1–2 (14 new sequences) were obtained. These show that Pentaplacodinium saltonense and Protoceratium reticulatum form two distinct clades. Pentaplacodinium saltonense forms a monophyletic clade with several unidentified strains from Malaysia. LSU and SSU rDNA sequences of three species of Ceratocorys (C. armata, C. gourreti, C. horrida) from the Mediterranean and several other unidentified strains from Malaysia form a well-supported sister clade. The unique phylogenetic position of an unidentified strain from Hawaii is also documented and requires further examination. In addition, based on the V9 SSU topology (bootstrap values >80%), specimens from Elands Bay (South Africa), originally described as Gonyaulax grindleyi by Reinecke (1967), cluster with Protoceratium reticulatum. The known range of Pentaplacodinium saltonense is tropical to subtropical, and its cyst is recorded as a fossil in upper Cenozoic sediments. Protoceratium reticulatum and Pentaplacodinium saltonense seem to inhabit different niches: motile stages of these dinoflagellates have not been found in the same plankton sample. info:eu-repo/semantics/acceptedVersion

Kolkwitziella acuta is a cyst-forming dinoflagellate with a unique tabulation, occurring in freshwater to brackish environments of Eurasia and the USA. Based on the unique thecal plate arrangement, this species was previously interpreted as a missing link in the evolution between the genus Protoperidinium and the Diplopsalioideae. We isolated living K. acuta cysts from the south-western Caspian Sea and the central Baltic (Finland), and re-established the cyst-theca relationship. The cysts had a distinctive polar and dorsoventral compression and a characteristic wrinkly texture. The plate formula of the thecate stage was Po, X, 4′, 2a, 7′′, 3c+t, ?s, 5′′′, 1′′′′. Large subunit (LSU) and small subunit (SSU) ribosomal DNA sequences obtained through single-cell PCR of these cysts reveal that this species is close to Protoperidinum excentricum which belongs to the Excentrica section of the genus Protoperidinium. We suggest that it evolved from the genus Diplopsalis through a split of the apical and anterior in...