Systematic Affinity Research Articles

Angiosperm diversification in the Early Cretaceous of Primorye, Far East of Russia

The Partizansk and Razdolnaya coal basins of Primorye, Far East of Russia, contain diverse early angiosperm fossils (pollen, leaves, and fruits). In this paper, we revise the previous data on early angiosperms of this region and summarize the results of our latest research. Age of the plant-bearing deposits was clarified using isotopic U-Th-Pb LA-ICP-MS and U-Pb ID-TIMS methods. Age of the upper part of the Lipovtsy Formation is 118 ± 1.4 Ma, which corresponds to the late Aptian. The early Albian age (109 ± 1 Ma) is assigned to the upper part of the Frentsevka Formation. The diversification of angiosperms in the Early Cretaceous of Primorye region and their systematic affinity are analyzed. Early representatives of Laurales, Ranunculales, Platanaceae, and probable Cercidiphyllaceae are revealed. New combination Pandanites ahnertii (Krysht.) Golovn., comb. nov. is created, and new species Araliaephyllum vittenburgii Golovn. et Volynets, sp. nov. is described. Reconstructions of herbaceous angiosperms from autochthonous locality Bolshoy Kuvshin are proposed.

A Tube-Dwelling Early Cambrian Lobopodian.

Facivermis yunnanicus [1, 2] is an enigmatic worm-like animal from the early Cambrian Chengjiang Biota of Yunnan Province, China. It is a small (<10cm) bilaterian with five pairs of spiny anterior arms, an elongated body, and a swollen posterior end. The unusual morphology of Facivermis has prompted a history of diverse taxonomic interpretations, including among annelids [1, 3], lophophorates [4], and pentastomids [5]. However, in other studies, Facivermis is considered to be more similar to lobopodians [2, 6-8]-the fossil grade from which modern panarthropods (arthropods, onychophorans, and tardigrades) are derived. In these studies, Facivermis is thought to be intermediate between cycloneuralian worms and lobopodians. Facivermis has therefore been suggested to represent an early endobenthic-epibenthic panarthropod transition [6] and to provide crucial insights into the origin of paired appendages [2]. However, the systematic affinity of Facivermis was poorly supported in a previous phylogeny [6], partially due to incomplete understanding of its morphology. Therefore, the evolutionary significance of Facivermis remains unresolved. In this study, we re-examine Facivermis from new material and the holotype, leading to the discovery of several new morphological features, such as paired eyes on the head and a dwelling tube. Comprehensive phylogenetic analyses using parsimony, Bayesian inference, and maximum likelihood all support Facivermis as a luolishaniid in a derived position within the onychophoran stem group rather than as a basal panarthropod. In contrast to previous studies, we therefore conclude that Facivermis provides a rare early Cambrian example of secondary loss to accommodate a highly specialized tube-dwelling lifestyle.

Protaxodioxylon from the Late Jurassic to Early Cretaceous Kota Formation, Pranhita-Godavari Basin, India

The xylotomy of the silicified wood from the Late Jurassic to Early Cretaceous Kota Formation of the Pranhita-Godavari Basin is studied and its systematic affinity is identified here. The wood is characterised by distinct growth rings with mixed pitting on radial tracheid walls, and taxodioid cross-field pits. The combination of the features observed in the present wood indicates that, it belongs to Protaxodioxylon of the taxodiaceous Cupressaceae s. l., as a new species Protaxodioxylon sahnii sp. nov. The comparison of wood with the modern representatives of the family suggests its relation with Taxodium. The present fossil wood with distinct growth rings characterised by their low percentage of latewood suggests that the growth conditions were favorable. The riparian habitat was inferred for the Protaxodioxylon sahnii sp. nov., based on sedimentological and other associated plant fossils. The vegetation in the study area is possibly favored by the influence of a subtropical climate with seasons, and by high levels of precipitation along the river banks.

Morphology and anatomy of the angiosperm fruit Baccatocarpon, incertae sedis, from the Maastrichtian Deccan Intertrappean Beds of India

Abstract Distinctive permineralized fruits of Baccatocarpon mohgaoense (Paradkar &amp; Dixit) comb. nov. have been collected from several sites in the late Maastrichtian of the Deccan Intertrappean beds of Central India. We describe the peculiar fruits in detail, based on combined investigations by reflected light and X-ray CT scanning. Three-dimensional renderings and virtual slices confirm that the fruits have two lateral single-seeded locules and a central sterile chamber filled with parenchyma. The endocarp is thin-walled and opens apically longitudinal valves. Here we validate the generic name Baccatocarpon Bhowal &amp; Sheikh ex Manchester, Ramteke, Kapgate &amp; S.Y. Smith and recognize a single species, for which the name Baccatocarpon mohgaoense (Paradkar &amp; Dixit) comb. nov. has priority. We document the occurrence of this species in cherts from the paleobotanical sites known as Bhutera, Keria, Mahurzari, Mohgoankalan, Paladaun, Marai Patan and Shibla. The systematic affinity of these fruits remains mysterious.

Systematic Affinity Purification Coupled to Mass Spectrometry Identified p62 as Part of the Cannabinoid Receptor CB2 Interactome.

The endocannabinoid system (ECS) consists particularly of cannabinoid receptors 1 and 2 (CB1 and CB2), their endogenous ligands, and enzymes that synthesize and degrade their ligands. It acts in a variety of organs and disease states ranging from cancer progression over neuropathic pain to neurodegeneration. Protein components engaged in the signaling, trafficking, and homeostasis machinery of the G-protein coupled CB2, are however largely unknown. It is therefore important to identify further interaction partners to better understand CB2 receptor functions in physiology and pathophysiology. For this purpose, we used an affinity purification and mass spectrometry-based proteomics approach of Strep-HA-CB2 receptor in HEK293 cells. After subtraction of background interactions and protein frequency library assessment we could identify 83 proteins that were classified by the identification of minimally 2 unique peptides as highly probable interactors. A functional protein association network analysis obtained an interaction network with a significant enrichment of proteins functionally involved in protein metabolic process, in endoplasmic reticulum, response to stress but also in lipid metabolism and membrane organization. The network especially contains proteins involved in biosynthesis and trafficking like calnexin, Sec61A, tubulin chains TUBA1C and TUBB2B, TMED2, and TMED10. Six proteins that were only expressed in stable CB2 expressing cells were DHC24, DHRS7, GGT7, HECD3, KIAA2013, and PLS1. To exemplify the validity of our approach, we chose a candidate having a relatively low number of edges in the network to increase the likelihood of a direct protein interaction with CB2 and focused on the scaffold/phagosomal protein p62/SQSTM1. Indeed, we independently confirmed the interaction by co-immunoprecipitation and immunocytochemical colocalization studies. 3D reconstruction of confocal images furthermore showed CB2 localization in close proximity to p62 positive vesicles at the cell membrane. In summary, we provide a comprehensive repository of the CB2 interactome in HEK293 cells identified by a systematic unbiased approach, which can be used in future experiments to decipher the signaling and trafficking complex of this cannabinoid receptor. Future studies will have to analyze the exact mechanism of the p62-CB2 interaction as well as its putative role in disease pathophysiology.

Xuanweioxylon damogouense sp. nov., a gymnosperm stem from the Lopingian (late Permian) of southwestern China and its systematic and paleoecological implications

A new species of permineralized gymnosperm stem is described from volcaniclastic tuffs in Lopingian (late Permian) Xuanwei Formation from eastern Yunnan province, China. The stem comprises well-preserved tissues of the pith, primary and secondary xylem. Pith is divided into a thick-walled parenchymatous peripheral zone and an inner parenchymatous part. Primary xylem strands are numerous and indistinct with mesarch maturation. Secondary xylem is pycnoxylic with scalariform bordered pits on radial tracheid walls, with rays normally uniseriate or partly biseriate. Cross-field pits are mixed and including circular, elliptical and scalariform pitting. Comparisons indicate a close affinity with the contemporaneous plant Xuanweioxylon scalariforme, but differences with it lead to the erection of Xuanweioxylon damogouense sp. nov. We evaluate the systematic affinity of both species of Xuanweioxylon and conclude they represent conifers based on features of their wood anatomy. We consider the Xuanwei Formation includes at least four species of conifer, and show that X. damogouense possessed weak growth rings and false rings that suggest it grew in a climate with low seasonality and occasional periods of drought.

Systematics and taphonomy of fossil woods from a new locality in the Upper Triassic Carrizal Formation of the El Gigantillo area (Marayes-El Carrizal Basin), San Juan, Argentina

We present a new locality with fossil woods in the southern outcrops of the Rickard Member, Carrizal Formation (Upper Triassic) of the El Gigantillo area in San Juan Province, Argentina. We analyzed the anatomical characters, systematic affinity and taphonomic conditions of permineralized trunks. A total of 58 trunks were found, although only two samples of the silicified trunks preserved anatomy details, and were characterized by a pycnoxylic homoxylic secondary wood with distinct growth rings, latewood 2–4 cells wide, tracheid pitting in radial walls of mixed type, cross-fields of cupressoid type with 1–4 oculipores, and homocellular and mainly uniseriate rays 1–19 cells high with smooth ray cell walls. The taphocenosis of the logs were preserved by carbonatic and siliceous permineralization, which are located in floodplains and channel deposits and constitute an allochthonous and parautochthonous taphocoenosis. The silicified wood presented high organic perturbation probably related to fungal activity, as well as several cylindrical and tubular galleries and pellets, which probably represented the activity of arthropods. The studied specimens were assigned to the new species Protocupressinoxylon carrizalense sp. nov. and constitute the first cite of the genus Protocupressinoxylon from the Triassic of Argentina. They thus represent the arboreal paleocommunities that grew in the top of the bars within the channels and riparian areas.

Analysis of NRAS RNA G-quadruplex binding proteins reveals DDX3X as a novel interactor of cellular G-quadruplex containing transcripts.

RNA G-quadruplexes (rG4s) are secondary structures in mRNAs known to influence RNA post-transcriptional mechanisms thereby impacting neurodegenerative disease and cancer. A detailed knowledge of rG4–protein interactions is vital to understand rG4 function. Herein, we describe a systematic affinity proteomics approach that identified 80 high-confidence interactors that assemble on the rG4 located in the 5′-untranslated region (UTR) of the NRAS oncogene. Novel rG4 interactors included DDX3X, DDX5, DDX17, GRSF1 and NSUN5. The majority of identified proteins contained a glycine-arginine (GAR) domain and notably GAR-domain mutation in DDX3X and DDX17 abrogated rG4 binding. Identification of DDX3X targets by transcriptome-wide individual-nucleotide resolution UV-crosslinking and affinity enrichment (iCLAE) revealed a striking association with 5′-UTR rG4-containing transcripts which was reduced upon GAR-domain mutation. Our work highlights hitherto unrecognized features of rG4 structure–protein interactions that highlight new roles of rG4 structures in mRNA post-transcriptional control.

Microproblematic organisms from the Norian–Rhaetian reefal carbonates of Saklıkent, Taurus Mountains, southern Turkey

Microscopic organisms with uncertain systematic affinity are referred to in the paleontological literature as microproblematica. Notwithstanding their cryptic biology, some are valuable index fossils for the facies analysis of reefal carbonates. Within reefal carbonates exposed near the town of Saklikent, Taurus Mountains, southern Turkey, many microproblematic organisms were found in thin-sections. All of these organisms are known from similar Norian–Rhaetian carbonates from other localities of the Tethys. They are briefly described here and their occurrence, abundance, and stratigraphic range, and their importance as facies and index fossils, are discussed, as well as their original interpretation. Some of these microproblematica are described for the first time from the Norian–Rhaetian interval of Turkey. A list of all known Triassic microproblematica, formal and informal taxa, is given as an appendix.

Complete mitochondrial genome of Sellanucheza jaegeri Golovatch, 2013 by next generation sequencing (Polydesmida: Paradoxosomatidae) and phylogenetic analysis in Diplopoda

The mitogenome of Sellanucheza jaegeri was 15,623 bp long, revealed the same gene order to that of typical Polydesmida. Both the tRNASer(AGN) and tRNASer(UCN) lacked the DHU arms. No tandem repeat was found in two control regions. Phylogenetic analysis indicated that Sphaerotheriida was so antiquity that divided out earlier than others. We supported that Polydesmida had a relatively systematic affinity between Julida and Playtdesmida, and suggested that the interordinal phylogenetic relationships within Diplopoda should be further investigated.

Occurrence of the earliest gigantopterid from the basal Permian of the North China Block and its bearing on evolution

Gigantopterids are a morphological group consisting of a number of enigmatic fossil plants with angiosperm‐like leaves and reticulate venation that are of uncertain systematic affinity. Gigantopterid plants were abundant and a characteristic floral element in the Late Palaeozoic Cathaysian floras. However, in China, their oldest occurrence was much later than that in North America (Artinskian) and Indonesia (Asselian to Sakmarian). Here, we document the gigantopterid Gigantonoclea cf. mira from basal Permian (Asselian) strata in the North China Block that represents the oldest unequivocal evidence for the gigantopterids. The foliage is characterized by complex venation composed of four orders, small isodiametric meshes, and intercalary subsidiary veins arising directly from the rachis, being a distinctive morphological type of leaf venation. In addition, a nonmarginal feeding trace is detected on the lamina, extending the earliest record of plant–animal interaction between gigantopterid plants and arthropods to the earliest Permian. Our new observations show that the venation characters of Gigantonoclea mira and Gigantonoclea cf. mira more closely resemble Gigantopteris dictyophylloides than other members of gigantopterids including the evolutionary Callipteridium sequence to which it was previously assigned.

Anatomically preserved "strobili" and leaves from the Permian of China (Dorsalistachyaceae, fam. nov.) broaden knowledge of Noeggerathiales and constrain their possible taxonomic affinities.

Noeggerathiales are an extinct group of heterosporous shrubs and trees that were widespread and diverse during the Pennsylvanian-Permian Epochs (323-252 Ma) but are of controversial taxonomic affinity. Groups proposed as close relatives include leptosporangiate ferns, sphenopsids, progymnosperms, or the extant eusporangiate fern Tmesipteris. Previously identified noeggerathialeans lacked anatomical preservation, limiting taxonomic comparisons to their external morphology and spore structure. We here document from the upper Permian of China the first anatomically preserved noeggerathialeans, which enhance the perceived distinctiveness of the group and better indicate its systematic affinity. We describe in detail the newly discovered, anatomically preserved heterosporous strobilus Dorsalistachya quadrisegmentorum, gen. et sp. nov., and redescribe its suspected foliar correlate, the pinnate leaf Plagiozamites oblongifolius. Plagiozamites possesses an omega (Ω)-shaped vascular trace and prominent cortical secretory cavities-a distinctive anatomical organization that is echoed in the newly discovered strobili. Dorsalistachya strobili bear highly dissected sporophylls alternately in two vertical rows, suggesting that they are homologs of leaf pinnae. If so, the "strobilus" is strictly a pseudostrobilus and consists of sporangium-bearing units that are one hierarchical level below true sporophylls. The "sporophylls" bear four microsporangia on the lower (abaxial) surface, occasionally interspersed with short longitudinal rows of megasporangia. A single functional megaspore develops within each winged megasporangium, suggesting adaptation for dispersal as a single unit. Dorsalistachya presents a unique combination of reproductive features that amply justifies establishment of a new family, Dorsalistachyaceae. Noeggerathiales represent a distinct taxonomic Order of free-sporing plants that most resembles early-divergent eusporangiate ferns and the more derived among the extinct progymnosperms. By the early Permian, noeggerathialeans had attained levels of reproductive sophistication similar to the most derived among the Paleozoic sphenophytes and lycophytes, but their heterosporous life history may have contributed to their extinction during the Triassic climatic aridification.

Early Oligocene plant diversity along the Upper Rhine Graben: The fossil flora of Rauenberg, Germany

Abstract The macroflora of Rauenberg, Baden-Württemberg, Germany, is treated monographically. The plant-bearing sediments are marine, mainly well-bedded clay- to siltstones, the so-called Fischschiefer, which are part of the Bodenheim Formation. Based on nannoplankton they are dated to nannoplankton zone NP 23 (Rupelian, Lower Oligocene). The plant remains, mainly leaves and some fructifications, are preserved as compressions. The taxonomic assignment is based on gross morphology and cuticle characteristics. The flora yields marine algae and remains of the very diverse terrestrial flora. A total of 68 taxa, including three types of algae, one cycad, 12 conifers, and 49 dicots, among them 5 palms, are described. The following fossil species are described for the first time: Laurophyllum rauenbergense, Myrica obliquifolia, Distylium metzleri, ? Berchemia altorhenana, ? Ternstroemites maritiae, Trachelospermum kelleri, Oleinites altorhenana, O. rauenbergensis, Dicotylophyllum badense, D. oechsleri, D. vesiculaeferens, D. ziegleri, ? Viscophyllum hendriksiae, and Cladites vesiculaeferens. Dicotylophyllum vesiculaeferens and Cladites vesiculaeferens bear peculiar, complex cuticular structures presumably representing salt-secreting glands. Both taxa are interpreted to derive from one plant species of yet uncertain systematic affinity. The flora bears a high proportion of broad-leaved, presumably evergreen taxa, whereas the diversity of modern Arcto-Tertiary taxa (sensu Kvaček 1994) is rather low. Most abundant are Platanus neptuni, Daphnogene cinnamomifolia, and Tetraclinis salicornioides. On the family level, Lauraceae (10 species) and Pinaceae (8) are most diverse, followed by Arecaceae (4-5), Cupressaceae, and Myricaceae (4 species each). Surprisingly, Fagaceae are documented solely by a single leaf of Eotrigonobalanus furcinervis f. haselbachensis, and the record of Pentaphyllaceae remains ambiguous (? Ternstroemites maritiae). Sloanea olmediaefolia is recorded for the first time from western parts of Europe. Remarkable is the presence of the rare cycad Ceratozamia floersheimensis. The following possible vegetation units are suggested: zonal broadleaved sclerophyllous evergreen forests and an intrazonal coastal pine-laurel-palm association on near-coastal sandy soils, as well as gallery forests along streams. No records of swampy environments were recovered. The climate may be characterised as follows: Cfa climate in transition to Cwa (and Am or Af) climate sensu Köppen, mean annual temperature 19-24°C, mean annual precipitation 1300-1700 mm, mean temperature of the warmest month 28-29°C, mean temperature of the coldest month 8-14°C, mean precipitation of the wettest month &gt;230 mm, mean precipitation of the driest month 18-38 mm, wettest month between May and October, driest month between November and March. The warm period was the wetter one. The flora from Rauenberg most closely resembles that of Flörsheim (Kvaček 2004a) and shows relations to the Paratethys realm, for example the Tard Clay Formation. Relations to the floras from Saxony, Saxony-Anhalt, and North Bohemia, similar in age, are rather restricted: broad-leaved deciduous taxa are much less diverse, and the numerous presumably evergreen taxa and palms present in Rauenberg have not been recorded in the other regions, indicating a more complex vegetation differentiation than a simple north-south gradient. The high number of taxa of uncertain affinity at Rauenberg points to the need for further taxonomic studies of the flora of this time interval. Comparisons with European assemblages of the early Oligocene reveal that the vegetation diversity in Europe during this time interval is far from being well understood.

The late Cretaceous Arman flora of Magadan oblast, Northeastern Russia

The Arman flora from the volcanogenic-sedimentary beds of the Arman Formation is systematically studied using materials from the Arman River basin and the Nelkandya-Khasyn interfluve (Magadan oblast, Northeastern Russia). Seventy-three species of fossil plants belonging to 49 genera are described. They consist of liverworts, horsetails, ferns, seed ferns, cycadaleans, bennettitaleans, ginkgoaleans, czekanowskialeans, conifers, gymnosperms of uncertain systematic affinity, and angiosperms. The Arman flora shows a unique combination, with relatively ancient Early Cretaceous ferns and gymnosperms occurring alongside younger Late Cretaceous plants, primarily angiosperms. The similarity of the Arman flora to the Penzhina and Kaivayam floras of northwestern Kamchatka and the Tylpegyrgynai flora of the Pekul’nei Ridge allows the Arman flora to be dated as Turonian and Coniacian (Late Cretaceous), which is corroborated by isotopic (U-Pb and 40Ar/39Ar) age determination for the plant-bearing layers.

Mass occurrence of the enigmatic gastropod Elmira in the Late Cretaceous Sada Limestone seep deposit in southwestern Shikoku, Japan

Elmira is a medium-to-large gastropod of uncertain systematic affinity, which has so far been reported only from a presumably Eocene methane-seep deposit in Cuba. This study reports a mass occurrence of Elmira shimantoensis Kiel and Nobuhara sp. nov. from a Late Cretaceous hydrocarbon-seep deposit in Shikoku, Japan, called the Sada Limestone. Its paleoecology is reconstructed based on its mode of occurrence, carbonate petrology, and stable carbon isotope analyses. The fauna of the Sada Limestone in general is characterized by an abundance of large chemosymbiotic bivalves of the family Thyasiridae and of “Serpula” tubes. The mass occurrence of Elmira shimantoensis was found in a lens-shaped carbonate body with a flat top and a concave base, 6.5 m in length and less than 2 m in thickness, consisting of multiple layers of shell accumulations, which were formed by shell-winnowing and the filling of a depression in slope mud. The scarcity of Elmira shimantoensis elsewhere in the Sada Limestone suggests that it formed locally from a gregarious population in the vicinity of the depression, possibly on hard ground. The matrix of the mass occurrence is rich in dolomite and ankerite, and is less depleted in 13C (δ13C values of calcite: −5.3 to −2.4 ‰; of dolomite: −8.3 ‰) than the matrix of the enclosing thyasirid-rich and tube-rich limestones. This suggests that the gastropod mass occurrence was cemented below the sulfate reduction zone and has thus undergone little anaerobic methane oxidation. Therefore, Elmira shimantoensis is reconstructed here as a bacteria grazer on a hard substrate such as exposed carbonate mounds rather than as a species that relied on chemosynthetic symbionts for nutrition.

Triassic Kykloxylon wood (Umkomasiaceae, Gymnospermopsida) from Skinner Ridge, northern Victoria Land, East Antarctica

During the first Korea Antarctic Geological Expedition (KAGEX I, 2013/2014), fossil wood was collected from the Triassic fluvial deposits of the Beacon Supergroup at Skinner Ridge in northern Victoria Land, Antarctica. The material is coalified and partially silicified; most specimens are slightly compressed due to burial compaction. In spite of this imperfect preservation, anatomical features of both the xylem and the pith could be observed in some specimens. The xylem displays prominent growth rings and usually araucarioid or somewhat mixed-type radial pitting with some abnormal rings partly composed of parenchymatous tissues. Some specimens also have a wood cylinder that is divided radially by parenchymatous zones. These anatomical features indicate a systematic affinity with Kykloxylon Mey.-Berth., T.N.Taylor et Ed.L.Taylor, a characteristic wood type of the Umkomaciaceae, which flourished throughout Gondwana during the Triassic. The Kykloxylon specimens in this study represent the only wood fossil taxon in the Triassic of Victoria Land, except for a dubious report of Antarcticoxylon Seward in 1914. This may indicate a low diversity of Triassic wood fossils in this area, as in other parts of Antarctica. On the contrary, diverse other gymnosperm organs are known to occur in the Triassic of Antarctica. This low diversity of wood taxa compared to the various plant organs in the Triassic of Antarctica is remarkable. We hypothesize three major reasons for this: 1) the overall structural uniformity of gymnosperm wood compared to other vegetative and especially reproductive organ diversity; 2) the overwhelming dominance of corystosperm plants, with a minor component of voltzialean conifers in the canopy-forming forest vegetation during the Triassic in Antarctica; and 3) the very few systematic studies of fossil wood compared to other plant macrofossils.

A new plant assemblage from the Middle Triassic volcanic tuffs of Pingchuan, Gansu, northwestern China and its paleoenvironmental significance

A new fossiliferous horizon from the Middle Triassic Dingjiayao Formation, Pingchuan District, Gansu Province, China is described. The plant assemblage preserves a diverse community of horsetails, ferns and seeds of unknown systematic affinity. Ferns are the most diverse elements of the assemblage and are also ecologically dominant, while horsetails contribute a smaller component to floristic diversity and have a lower abundance. Here, five fern taxa are assigned to Marantoidea, Symopteris, Neuropteridium, Cladophlebis and Sphenopteris. Also, six species belonging to three horsetail taxa are described from this assemblage, which are assigned to Equisetites, Echinostachys and Neocalamites. Additionally, remains of doubtful botanical attribution comprise Carpolithus seeds. Some of these groups are recorded from the Middle Triassic of China for the first time. The preservation of these fossils suggests that the assemblage was buried autochthonously or para-autochthonously by volcanic ash fall. Fossilization of these specimens occurred rapidly after the specimens embedded in the volcaniclastic sediments. Also the plant assemblage indicates a local riparian environment in a warm, humid climate.

Extracellular polysaccharides from Ascomycota and Basidiomycota: production conditions, biochemical characteristics, and biological properties.

Fungal polysaccharides (PSs) are the subject of research in many fields of science and industry. Many properties of PSs have already been confirmed and the list of postulated functions continues to grow. Fungal PSs are classified into different groups according to systematic affinity, structure (linear and branched), sugar composition (homo- and heteropolysaccharides), type of bonds between the monomers (β-(1 → 3), β-(1 → 6), and α-(1 → 3)) and their location in the cell (cell wall PSs, exoPSs, and endoPSs). Exopolysaccharides (EPSs) are most frequently studied fungal PSs but their definition, classification, and origin are still not clear and should be explained. Ascomycota and Basidiomycota fungi producing EPS have different ecological positions (saprotrophic and endophytic, pathogenic or symbiotic-mycorrhizae fungi); therefore, EPSs play different biological functions, for example in the protection against environmental stress factors and in interactions with other organisms. EPSs obtained from Ascomycota and Basidiomycota fungal cultures are known for their antioxidant, immunostimulating, antitumor, and antimicrobial properties. The major objective of the presented review article was to provide a detailed description of the state-of-the-art knowledge of the effectiveness of EPS production by filamentous and yeast Ascomycota and Basidiomycota fungi and techniques of derivation of EPSs, their biochemical characteristics, and biological properties allowing comprehensive analysis as well as indication of similarities and differences between these fungal groups. Understanding the role of EPSs in a variety of processes and their application in food or pharmaceutical industries requires improvement of the techniques of their derivation, purification, and characterization. The detailed analyses of data concerning the derivation and application of Ascomycota and Basidiomycota EPSs can facilitate development and trace the direction of application of these EPSs in different branches of industry, agriculture, and medicine.

Fungal colonization of the rooting system of the early land plantAsteroxylon mackieifrom the 407-Myr-old Rhynie Chert (Scotland, UK)

Associations between plants and fungi were an important and varied feature of early terrestrial ecosystems, but in most instances their biological functions remain poorly understood. We document a new species of fungus colonizing the rooting system of the early lycopod Asteroxylon mackiei, based on exceptionally well-preserved fossils from the Rhynie Chert. We investigated historical petrographic thin sections using standard optical microscopy and confocal laser scanning microscopy. Palaeozoosporites renaultii gen. nov., sp. nov. colonized the inner cortex of the plant rooting system. The fungus had an aseptate thallus with isotomous or sympodial branching. The mycelium bore distinctive porate, globose to elongated structures that we interpret as zoosporangia and resting sporangia. Doubts remain over the precise systematic affinity of P. renaultii, which closely resembles chytrids. Whereas most of the Rhynie Chert plants developed symbiotic associations of the mycorrhizal type, it seems that this was not the case for Asteroxylon mackiei, which possessed the most evolved rooting system among the Rhynie Chert plants. We argue that the new root-borne fungus was probably parasitic. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179, 201–213.

Early Middle Jurassic (possibly Aalenian) Tsagan-Ovoo Flora of Central Mongolia

The Tsagan-Ovoo Flora from terrigenous, coal-bearing deposits of the Bakhar Formation, central Mongolia, is documented for the first time. The Tsagan-Ovoo Flora contains 32 megafossil plant taxa belonging to horsetails, ferns, cycadaleans, ginkgoaleans, leptostrobaleans, conifers and gymnosperms of unknown systematic affinity. The floristic composition of the plant-bearing beds allows us to date them as early Middle Jurassic (possibly Aalenian). This flora is typical of the West Siberian Province of the Siberian Region and corroborates our previously obtained conclusion that the boundary between this province and the North Chinese Province of the same region should be positioned further south than its previous placement. The plants of the Tsagan-Ovoo Flora probably formed a mosaic of communities that inhabited swampy lowlands and lake margins. The flora reflects a wet, most probably warm-temperate climate with some seasonality in temperature and/or precipitation. Three new ginkgoalean species of the Tsagan-Ovoo Flora are described: Ginkgo badamgaravii Kostina et Herman, Pseudotorellia gobiense Kostina et Herman, and Pseudotorellia mongolica Kostina et Herman.