Ankistrodinium armigerum sp. nov. (Dinophyceae), a new species of heterotrophic marine sand‐dwelling dinoflagellate from Japan and Australia

A new heterotrophic sand‐dwelling dinoflagellate, Ankistrodinium armigerum K. Watanabe, Miyoshi, Kubo, Murray et Horiguchi sp. nov., is described from Ishikari Beach, Hokkaido, Japan and Port Botany, NSW, Australia. The dinoflagellate is laterally compressed, possessing a short triangular epicone and a large sac‐like hypocone. It possesses a right‐handed cingulum and a deeply‐incised sulcus. The sulcus descends towards the posterior of the cell where it becomes much deeper and wider, resulting in a bilobed ventral side to the hypocone, with a greater excavation of the left lobe than the right. In addition, the right lobe of the hypocone is shorter than the left lobe, which allows a partial view of the left sulcal wall when the cell is viewed from its right side. The sulcus ascends in the epicone to form an apical groove. The apical groove is linear but terminates in an ellipsoid fashion and its extremity approaches, but does not form a closed loop with the apical end of the linear portion. The dinoflagellate possesses two distinct size classes of trichocysts. The large trichocysts are located in the posterior part of the cell, while small trichocysts are distributed throughout the cell. The dinoflagellate shares morphological characteristics with the heterotrophic sand‐dwelling dinoflagellate, Ankistrodinium semilunatum, the type species of the genus. These include a laterally compressed cell, a right‐handed cingulum, a deeply‐incised sulcus and the same basic structure to the apical groove. Molecular phylogenetic analyses based on small and large subunits of rDNA showed that in both trees, A. semilunatum and A. armigerum formed a robust clade, suggesting that these two species are closely related. Because no organism with the characteristics of this species exists and because this species is closely related to A. semilunatum, we concluded that this species should be described as a second species of the genus Ankistrodinium.     

Amphidiniella sedentaria gen. et sp. nov. (Dinophyceae), a new sand-dwelling dinoflagellate from Japan

A new sand-dwelling dinoflagellate is described from Sesoko Beach, Okinawa Island, subtropical Japan and its micromorphology is studied by means of light and electron microscopy. The cell consists of a small epitheca and a large hypothecs superficially resembling members of the unarmored genus Amphidinium. The cell is dorso-ventrally flattened and possesses a single chloroplast with a large conspicuous pyrenoid. Transmission electron microscopy revealed that the dinoflagellate possesses typical dinoflagellate cellular organization. Scanning electron microscopy demonstrated that the organism is thecate and the thecal plate arrangement is Po, 4′, 1a, 7″, 5c, 4s, 6″′, 2″″. Most of the characteristics suggest gonyaulacalean affinity of the new species. These are the presence of ventral pore, lack of canal plate, direct contact between the sulcal anterior plate and the flagellar pore, possession of six postcingular plates and asymmetrical arrangement of the antapical plates. Affinity to existing families of the order Gonyaulacales has not been determined. Based on the unique cell shape, thecal plate arrangement and the presence of ventral pore, a new genus, Amphidiniella, is established for this organism and the species is named A. sedentaria Horiguchi gen. et sp. nov.     

Testudodinium gen. nov. (Dinophyceae), a new genus of sand‐dwelling dinoflagellates formerly classified in the genus Amphidinium

A new genus of sand‐dwelling photosynthetic dinoflagellate, Testudodinium Horiguchi, Tamura, Katsumata et A. Yamaguchi is proposed based on Testudodinium testudo (Herdman) Horiguchi, Tamura, Katsumata, et A. Yamaguchi comb. nov. (Basionym: Amphidinium testudo Herdman) and a new species in this new genus, Testudodinium maedaense Katsumata et Horiguchi sp. nov. is described. Amphidinium corrugatum is also transferred to this genus, making a new combination T. corrugatum (Larsen et Patterson) Horiguchi, Tamura et A. Yamaguchi. These three species are similar to the members of the genus Amphidinium in having an extremely small episome and a dorsoventrally flattened cell body. They are, however, distinguished from the genus Amphidinium seusu stricto by the possession of a distinct longitudinal furrow in the middle of ventral side of the episome. Phylogenetic trees based on small subunit (SSU) rDNA revealed that all three of these Testudodinium species formed a robust clade and, although statistical support is not high, the tree suggests Testudodinium clade is not closely related to Amphidinium seusu stricto clade. The morphological differences together with molecular data support the establishment of a new genus for A. testudo and its related species.     

Pyramidodinium atrofuscum gen. et sp. nov. (Dinophyceae), a new marine sand-dwelling coccoid dinoflagellate from tropical waters

A new marine sand‐dwelling coccoid dinoflagellate Pyramidodinium atrofuscum Horiguchi et Sukigara gen. et sp. nov. is described from Jellyfish Lake, Republic of Palau. The dinoflagellate alternates a non‐motile vegetative stage with a motile gymnodinioid stage within its life cycle. The non‐motile stage is dominant in the life cycle and the dinoflagellate reproduces itself by means of the production of two motile cells. The released motile cell swims only for a short period and is directly transformed into the non‐motile cell. The non‐motile cell is sessile, pyramidal in shape, with a single longitudinal ridge and a double transverse ridge. The surface of the cell wall is covered with many processes. The motile cell has a Gymnodinium‐like morphology, but no apical groove is present. An ultrastructural study revealed that the dinoflagellate possesses typical dinoflagellate organelles. Based on the unique morphology of the vegetative non‐motile stage, we propose a new genus Pyramidodinium for this dinoflagellate, with the type species Pyramidodinium atrofuscum Horiguchi et Sukigara, gen. et sp. nov.     

Gymnoxanthella radiolariae gen. et sp. nov. (Dinophyceae), a dinoflagellate symbiont from solitary polycystine radiolarians

The symbiotic dinoflagellate Gymnoxanthella radiolariae T. Yuasa et T. Horiguchi gen. et sp. nov. isolated from polycystine radiolarians is described herein based on light, scanning and transmission electron microscopy as well as molecular phylogenetic analyses of SSU and LSU rDNA sequences. Motile cells of G. radiolariae were obtained in culture, and appeared to be unarmored. The cells were 9.1–11.4 μm long and 5.7–9.4 μm wide, and oval to elongate oval in the ventral view. They possessed an counterclockwise horseshoe‐shaped apical groove, a nuclear envelope with vesicular chambers, cingulum displacement with one cingulum width, and the nuclear fibrous connective; all of these are characteristics of Gymnodinium sensu stricto (Gymnodinium s.s.). Molecular phylogenetic analyses also indicated that G. radiolariae belongs to the clade of Gymnodinium s.s. However, in our molecular phylogenetic trees, G. radiolariae was distantly related to Gymnodinium fuscum, the type species of Gymnodinium. Based on the consistent morphological, genetic, and ecological divergence of our species with the other genera and species of Gymnodinium s.s., we considered it justified to erect a new, separate genus and species G. radiolariae gen. et sp. nov. As for the peridinioid symbiont of radiolarians, Brandtodinium has been erected as a new genus instead of Zooxanthella, but the name Zooxanthella is still valid. Brandtodinium is a junior synonym of Zooxanthella. Our results suggest that at least two dinoflagellate symbiont species, peridinioid Zooxanthella nutricula and gymnodinioid G. radiolariae, exist in radiolarians, and that they may have been mixed and reported as “Z. nutricula” since the 19th century.     

Pyramidodinium spinulosum sp. nov. (Dinophyceae), a sand‐dwelling non‐motile dinoflagellate from the seafloor (36 m deep) off Mageshima Island,Kagoshima, Japan

A new species of benthic marine dinoflagellate, Pyramidodinium spinulosum Horiguchi, Moriya, Pinto & Terada is described from the deep (36 m) seafloor off Mageshima Island, Kagoshima Prefecture, Japan in the subtropical region of the northwest Pacific. The life cycle of the dinoflagellate consists of a dominant, attached, dome‐shaped, vegetative form and short‐lasting, motile cell. Asexual reproduction takes place by the formation of two motile cells within each non‐motile cell. The released motile cells swim only for a short period and transform directly into the dome‐shaped vegetative form. The duration of the cell cycle varies and can be extremely long, ranging 5–38 days under culture conditions. The non‐motile cell is enclosed by a cell wall and its surface is covered with many (80 – 130) spines of various length. The dinoflagellate is photosynthetic and contains many (more than 50) discoidal chloroplasts. Phylogenetic analysis reveals that the dinoflagellate is closely related to the type species of the genus Pyramidodinium, P. atrofuscum which also possesses a dominant, attached, non‐motile form. However, P. spinulosum can be clearly distinguished from P. atrofuscum by the cell shape (dome‐shaped vs. pyramid‐shaped) and surface ornamentation (spines vs. wart‐like processes) of the non‐motile form. Based on these morphological differences together with molecular evidence, it was concluded that this organism from a deep water sand sample should be described as a second species of the genus Pyramidodinium, P. spinulosum.     

Haramonas dimorpha gen. et sp. nov. (Raphidophyceae), a new marine raphidophyte from Australian mangrove*

A new raphidophyte flagellate is described from the river mouth of the Daintree River, north-east Australia where there are extensive mangrove forests. The organism has two distinct phases: a club-shaped motile form, and a more or less spherical benthic non-motile form. The motile cell is metabolic and possesses 10–20 chloroplasts. The chloroplasts are imbricated, somewhat reminiscent of roofing tiles. A unique structure has been found at the posterior end of the cell. It is a tubular invagination, which consists of a single membrane supported by many small flattened vesicles. In addition, the structure is surrounded by many fibril-containing vesicles. The tubular invagination is different from both the contractile vacuoles and the pusules of dinoflagellates in both behavior and structure. Based on the possession of these unique features, it is concluded that the this mangrove flagellate should be described as a new species in a new genus and the name Haramonas dimorpha Horiguchi gen. et sp. nov. is proposed.     

Laciniporus arabicus gen. et sp. nov. (Dinophyceae,Peridiniales), a new thecate,marine, sand‐dwelling dinoflagellate from the northern Indian Ocean (Arabian Sea)1

A new thecate, photosynthetic, sand‐dwelling marine dinoflagellate, Laciniporus arabicus gen. et sp. nov., is described from the subtidal sediments of the Omani coast in the Arabian Sea, northern Indian Ocean, based on detailed morphological and molecular data. Cells of L. arabicus are small (16.2–30.1 μm long and 13.1–23.2 μm wide), dorsoventrally compressed, with a small apical flap‐shaped projection pointing to the left. The thecal plate pattern is distinguished by minute first precingular plate and sulcus, which extends into the epitheca, with large anterior and right sulcal plates. The Kofoidian thecal tabulation is Po, X, 4′, 2a, 7′′, 6c, 6s, 5′′′, 2′′′′. Morphologically, the revealed plate pattern has an affinity to the Peridiniales, and LSU rDNA based phylogenetic analyses placed L. arabicus within the Thoracosphaeraceae, close to calcareous‐cyst producing scrippsielloids, predatory pfiesteriaceans, and photosynthetic freshwater peridinioids Chimonodinium lomnickii and Apocalathium spp. However, the thecal plate arrangement of L. arabicus differs noticeably from any currently described dinoflagellates, and the species stands out from closely related taxa by extensive differences in physiology and ecology.     

GALEIDINIIUM RUGATUM GEN. ET SP. NOV. (DINOPHYCEAE), A NEW COCCOID DINOFLAGELLATE WITH A DIATOM ENDOSYMBIONT1

A new sand‐dwelling dinoflagellate from Palau, Galeidinium rugatum Tamura et Horiguchi gen. et sp. nov., is described. The life cycle of this new alga consists of a dominant nonmotile phase and a brief motile phase. The motile cell transforms itself directly into the nonmotile cell after swimming for a short period, and cell division takes place in the nonmotile phase. The nonmotile cell possesses a dome‐like cell covering, which is wrinkled and equipped with a transverse groove on the surface. The cell has 10–20 chloroplasts and a distinct eyespot. The motile cell is Gymnodinium‐like in shape. The dinoflagellate possesses an endosymbiotic alga to which the chloroplasts belong and which is separated from the host (dinoflagellate) cytoplasm by a unit membrane. The endosymbiont cytoplasm also possesses its own eukaryotic nucleus and mitochondria. The eyespot is surrounded by triple membranes and is located in the host cytoplasm. Photosynthetic pigment analysis, using HPLC, revealed that G. rugatum possesses fucoxanthin as the principal accessory pigment instead of peridinin. The rbcL tree showed that G. rugatum is monophyletic with Durinskia baltica (Levander) Carty et Cox and Kryptoperidinium foliaceum (Stein) Lindemann and that this clade is closely related to the pennate diatom, Cylindrotheca sp. The endosymbiont of G. rugatum is therefore shown to be a diatom. Phylogenetic analysis based on small subunit rDNA sequences demonstrated that G. rugatum, D. baltica, and K. foliaceum, all of which are known to harbor an endosymbiont of diatom origin, are closely related.     

Heterocapsa psammophila sp. nov. (Peridiniales, Dinophyceae), a new sand-dwelling marine dinoflagellate

A new armored dinoflagellate species, Heterocapsa psammophila Tamura, Iwataki et Horiguchi sp. nov. is described from Kenmin‐no‐hama beach, Hiroshima, Japan using light and electron microscopy. This dinoflagellate possesses the typical thecal plate arrangement of the genus Heterocapsa, Po, cp, 5′, 3a, 7′′, 6c, 5s, 5′′′, 2′′′′; and the 3‐D body scales of Heterocapsa on the plasma membrane. The cell shape is ovoidal. The spherical nucleus and the pyrenoid are situated in the hypotheca and the epitheca, respectively. The ultrastructure of H. psammophila is typical of dinoflagellates and the pyrenoid is invaginated by cytoplasmic tubules. H. psammophila is distinguished from all other hitherto‐described Heterocapsa species by the cell shape, the relative position of the nucleus and pyrenoid and the structure of the body scale. The habitat and behavior of this new species in culture suggest that the organism is truly a sand‐dwelling species.     

An ultrastructural study of Marsupiomonas pelliculata gen. et sp. nov., a new member of the Pedinophyceae

A new species, Marsupiomonas pelliculata gen. et sp. nov. (Pedinophyceae), is described. A single flagellum emerges from a deep pit with a distinctive thickened margin. The flagellum has rigid fibrillar hairs which are probably formed in the perinuclear space. A short second flagellar basal body lies within the cell close to the basal body of the emergent flagellum and the flagellar root system consists of striated and microtubular roots. There is a distinctive theca covering all but the anterior end of the cell and also a single large bright green chloroplast with an immersed pyrenoid surrounded by a starch shell. The wide salinity tolerance of the species is discussed in relation to its distribution in estuarine and salt marsh habitats. The salient features of the new species—the insertion of the emergent flagellum into a deep pit and the possession of a theca—are also seen in Pedinomonas tenuis, and it is suggested that P. tenuis could be transferred to the new genus Marsupiomonas. The class Pedinophyceae now includes three genera (Pedinomonas, Resultor and Marsupiomonas) and the distinguishing features are discussed.     

Molecular phylogeny and taxonomy of the genus Chaetophora (Chlorophyceae,Chlorophyta), including descriptions of Chaetophoropsis aershanensis gen. et sp. nov.

The broadly defined genus Chaetophora consisted of species with minute, uniseriate branching filaments enveloped in soft or firm mucilage forming macroscopic growths that are spherical, hemispherical, and tubercular or arbuscular, growing epiphytically on freshwater aquatic plants and other submerged surfaces in standing or fast‐flowing water. Recent molecular analyses clearly showed that this genus was polyphyletic. In this study, eight strains of Chaetophora and three strains of Stigeoclonium were identified and successfully cultured. In combination with the morphological data, a concatenated data set of four markers (18S + 5.8S + ITS2+ partial 28S rDNA) was also used to determine their taxonomic relationships and phylogenetic positions. The molecular analysis resolved the broadly defined Chaetophora to at least two genera. Species with a globose thallus of genus Chaetophora formed a separate monophyletic clade, which clearly separated from, a type of lobe‐form Chaetophora species. Therefore, we propose to erect a new genus, Chaetophoropsis, which includes all globose species of the Chaetophora. Chaetophoropsis aershanensis was determined to be a new species, based on its special characteristic of profuse long rhizoids. Stigeoclonium polyrhizum, as the closest relative to Chaetophoropsis, revealed its distant relationships to other species of Stigeoclonium. A globose thallus with a thick, soft mucilage matrix, and special rhizoidal branches lent further support to the placement of S. polyrhizum in the genus Chaetophoropsis and had the closest relationship to C. aershanensis. Taxonomic diversity was proven by distinctive morphological differences and by phylogenetic divergence in the broadly defined Chaetophora identified herein.     

Multi‐gene phylogenetic analyses of New Zealand coralline algae: Corallinapetra Novaezelandiae gen. et sp. nov. and recognition of the Hapalidiales ord. nov.

Coralline red algae from the New Zealand region were investigated in a study focused on documenting regional diversity. We present a multi‐gene analysis using sequence data obtained for four genes (nSSU, psaA, psbA, rbcL) from 68 samples. The study revealed cryptic diversity at both genus and species levels, confirming and providing further evidence of problems with current taxonomic concepts in the Corallinophycidae. In addition, a new genus Corallinapetra novaezelandiae gen. et sp. nov. is erected for material from northern New Zealand. Corallinapetra is excluded from all currently recognized families and orders within the Corallinophycidae and thus represents a previously unrecognized lineage within this subclass. We discuss rank in the Corallinophycidae and propose the order Hapalidiales.     

Studies of the Liagoraceae (rhodophyta) of Western Australia: Gloiotrichus fractalis gen. et sp. nov. and Ganonema helminthaxis sp. nov.

Two new taxa of Liagoraceae (Nemaliales) are described from Western Australia. Gloiotrichus fractalis gen. et sp. nov. has been collected from 3–20 m depths at the Houtman Abrolhos, Western Australia. Plants are calcified, extremely lubricous, and grow to 17 cm in length. Carpogonial branches are straight, 6 or 7 cells in length, arise from the basal or lower cells of cortical fascicles, and are occasionally compound. Branched sterile filaments of narrow elongate cells arise on the lower cells of the carpogonial branch prior to gonimoblast initiation, at first on the basal cells, then on progressively more distal cells. Following presumed fertilisation the carpogonium divides transversely, with both cells giving rise to gonimoblast filaments. The distal cells of the carpogonial branch then begin to fuse, with fusion progressing proximally until most of the cells of the carpogonial branch are included. As fusion extends, the filaments on the carpogonial branch are reduced to the basal 2 or 3 cells. The gonimoblast is compact and bears terminal carposporangia. Spermatangial clusters arise on subterminal cells of the cortex, eventually displacing the terminal cells. The sequence of pre- and post-fertilisation events occurring in the new genus separates it from all others included in the Liagoraceae, although it appears to have close affinities with the uncalcified genus Nemalion. Ganonema helminthaxis sp. nov. was collected from 12 m depths at Rottnest Island, Western Australia. Plants are uncalcified and mucilaginous, the axes consisting of a few (< 10) primary medullary filaments, each cell of which gives rise to a cortical fascicle at alternate forks of the pseudodichotomies borne on successive medullary cells. Subsidiary (adventitious) filaments and rhizoids comprise the bulk of the thallus. Carpogonial branches are straight, (3-)4(-6) cells in length, arise on the basal 1–4 cells of the cortical fascicles, and are frequently compound. Carposporophytes develop from the upper of two daughter cells formed by a transverse division of the fertilised carpogonium. Ascending and descending sterile filaments girdle the carpogonial branch cells and arise mostly on the supporting cell prior to fertilisation. Ganonema helminthaxis is the first completely non-calcified member of the genus, and its reproductive and vegetative morphology supports the recognition of Ganonema as a genus independent from Liagora. Liagora codii Womersley is a southern Australian species displaying features of Ganonema, to which it is transferred.     

Cochlodinium fulvescens sp. nov. (Gymnodiniales, Dinophyceae), a new chain-forming unarmored dinoflagellate from Asian coasts

Cellular morphology and the phylogenetic position of a new unarmored photosynthetic dinoflagellate Cochlodinium fulvescens Iwataki, Kawami et Matsuoka sp. nov. were examined by light microscopy and molecular phylogenetic analyses based on partial large subunit ribosomal DNA (LSU rDNA) and small subunit ribosomal DNA (SSU rDNA) sequences. The cells of C. fulvescens closely resemble C. polykrikoides, one of the most harmful red tide forming dinoflagellates, due to it possessing a cingulum encircling the cell approximately twice, a spherical nucleus positioned in the anterior part of the cell and an eyespot‐like orange pigmented body located in the dorsal side of the epicone, as well as formation of cell‐chains. However, this species is clearly distinguished from C. polykrikoides based on several morphological characteristics, namely, cell size, shape of chloroplasts and the position of narrow sulcus situated in the cell surface. The sulcus of C. fulvescens is located at the intermediate position of the cingulum in the dorsal side, whereas that of C. polykrikoides is situated immediately beneath the cingulum. LSU rDNA phylogenies indicated that C. fulvescens is clearly distinct from, but closely related to C. polykrikoides among dinoflagellates.     

Laminarionema elsbetiae gen. et sp. nov. (Ectocarpales, Phaeophyceae), a new endophyte in Laminaria sporophytes

Laminarionema elsbetiae gen. et sp, nov, (Ectocarpaceae, Ectocarpales. Phaeophyceae), a new endophyte of Laminaria japonica Areschoug (Laminariales, Phaeophyceae), is described from Muroran. Hokkaido, Japan. Laminarionema elsbetiae grows in the host tissues forming networks in the epidermal and subcortical layers as well as penetrating into the cortical and medullary layers. Only phaeophycean hairs emerge from the surface of the host tissue. No reproductive cells were found in field material. However, under host-free culture the species formed three morphologically different reproductive structures. Macrosporangia containing a single large motile spore were formed under long and short day conditions below 20°C, transformed from vegetative cells, conical to elongated in shape, 50–75 μm in length and ca. 10 μm in diameter. Microsporangia were linear to lanceolate, sometimes branched, formed under long and short day conditions below 15°C. Unilocular sporangia were more or less irregular in shape, formed under short day conditions of 5–15°C, 60–75 μm in length and 40–45 μm in diameter. Sexual fusion between macro- and microspores was not seen. In mixed cultures of L. elsbetiae with young sporophytes of L Japonica Areschoug as well as Saccorhiza dermatodea (de la Pylaie) J. Agardh, L elsbetiae infected both hosts, grew in the same manner as in natural hosts, and formed macrosporangia between host epidermal cells.     

Protoperidinium tricingulatum sp. nov. (Dinophyceae), a new motile form of a round,brown, and spiny dinoflagellate cyst

A small, broadly ovoidal and heterotrophic dinoflagellate containing round, brownish, and spiny cyst was found in the water column of Huibertsplaat in the Wadden Sea off the coast of the Netherlands. This dinoflagellate had these conspicuous morphological characters: a five‐sided first apical plate (1′), only three cingular plates, and an extremely small first antapical plate. Based on these morphological features, Protoperidinium tricingulatum Kawami, vanWezel, Koeman et Matsuoka is described as a new species. The flagellar pore of P. tricingulatum is covered with a small fin, which rises from the left side of the right sulcal plate to the large V‐shaped posterior sulcal plate. This feature suggests that P. tricingulatum is assigned to the Abé's Monovela Group. The cyst stage of P. tricingulatum was positively linked to the vegetative stage by comparison of the ribosomal 5.8S rDNA, internal transcribed spacers (ITS1 and ITS2). Living cysts of P. tricingulatum are round, brownish, and covered with many slender spines bearing capitate or cauliforate distal ends. The cyst also possesses a theropylic archeopyle formed by a slit corresponding to parasutures between three apical and two apical intercaraly plates. These morphological characters indicate that this species is morphologically related to two dinoflagellate cyst‐genera Islandinium and Echinidinium.     

Xenococconeis opunohusiensis gen. et sp. nov. and Xenococconeis neocaledonica comb. nov. (Bacillariophyta) from the tropical South Pacific

During a survey of the coral reef diatoms of Moorea Island (Society Archipelago, South Pacific) a small‐sized member of the order Achnanthales was studied using a light microscope (LM) and a scanning electron microscope (SEM). This marine taxon has: a raphe valve (RV) with a non‐crenulate edge; a high cingulum; a sternum valve (SV) often irregularly striated and areolae with concave hymenate pore occlusion; a thick and plain SV valvocopula (SVVC), ring‐shaped, composed of large fused fimbriae, with a central elliptic foramen bordered by the peg‐like edge of the fimbriae. On abvalvar side, the SVVC bears radiate concave and robust transapical ribs, interlinking with short elevated transverse ribs of the RV valvocopula (RVVC). Large marginal fenestrae of the RVVC give access to pseudoloculi. One oblong, unique and striated papilla is located on each RVVC rib. Given this unique set of features, we describe Xenococconeis opunohusiensis gen. et sp. nov. as a new taxon belonging to the Achnanthales. The characteristics of the new taxon are compared with Campyloneis Grunow and Cocconeis Ehrenberg. From New Caledonia, Cocconeis neocaledonica Maillard ex Lange‐Bertalot et Steindorf, a freshwater diatom, was described with two internal septa with marginal pseudoloculi. Based on subsequent SEM illustrations and remarks, we propose the transfer of C. neocaledonica to the new genus, and compare it to the type species, Xenococconeis opunohusiensis.     

Hironoia fusiformis gen. et sp. nov.; a cornalean fruit from the Kamikitaba locality (Upper Cretaceous,Lower Coniacian) in northeastern Japan

The application of sieving techniques to bulk samples from the Ashizawa Formation, Futaba Group (Lower Coniacian) of northeastern Honshu, Japan, has yielded well-preserved mesofossil assemblages comparable with those recently described from eastern North America, Europe, and central Asia. Among the most abundant and distinctive components of these assemblages are fusiform fruits that are assigned here to a new genus and species, Hironoia fusiformis gen. et sp. nov. The fruits developed from an epigynous ovary with three to four locules. Each locule bears one seed and has a distinctive dorsal germination valve. These features of the fruit, along with the adnate calyx, indicate an affinity to extant Cornales and specifically the Cornaceae sensu lato. The recognition of an unequivocal cornalean fruit in the Early Coniacian–Early Santonian of Japan provides the earliest record of this group in the fossil record. It also establishes a minimum age for the early divergence of the asterid clade, a major group of living angiosperms comprising more than a third of all species of extant flowering plants. Electronic Publication