Fungal Remains Research Articles

Structurally preserved fungi from Antarctica: diversity and interactions in late Palaeozoic and Mesozoic polar forest ecosystems

AbstractChert and silicified wood from the Permian through Cretaceous of Antarctica contain abundant information on fungal diversity and plant–fungal interactions. The chert deposits represent a particularly interesting setting for the study of plant–fungal interactions because they preserve remains of distinctive high latitude forest ecosystems with polar light regimes that underwent a profound climate change from icehouse to greenhouse conditions. Moreover, some of the cherts and wood show the predominance of extinct groups of seed plants (e.g. Glossopteridales, Corystospermales). Over the past 30 years, documentation of fossil fungi from Antarctica has shifted from a by-product of plant descriptive studies to a focused research effort. This paper critically reviews the published record of fungi and fungal associations and interactions in the late Palaeozoic and Mesozoic cherts and silicified wood from Antarctica; certain fungal palynomorphs and fungal remains associated with adpression fossils and cuticles are also considered. Evidence of mutualistic (mycorrhizal), parasitic and saprotrophic fungi associated with plant roots, stems, leaves and reproductive organs is presented, together with fungi occurring within the peat matrix and animal–fungus interactions. Special attention is paid to the morphology of the fungi, their systematic position and features that can be used to infer fungal nutritional modes.

A comparative palynological study on butterfly mud puddling localities and surface forest samples: a case study from northeast India

This paper presents a palynological examination of surface soil samples procured from butterfly mud puddling locations in northeast India and its comparison with forest surface samples from the immediate vicinity. The modern palynodata from different sites reflect a close similarity in the types and frequency of the pollen grains. However, the diversity of pollen taxa in butterfly mud puddle samples was comparatively higher than the forest surface samples. The pollen recovered in both the butterfly mud puddle location and forest surface samples reflects an evergreen forest composed of Dillenia, Elaeocarpus, Litsea, and Syzygium which exactly displays the current vegetation. The presence of cerealia, along with Brassicaceae, and Hibiscus in the butterfly mud puddle samples is suggestive of the human activity in the vicinity. However, the abundance of Lantana and Melastoma pollen in the mud puddle sediments is a strong indication of the conversion of forest vegetation in to open habitat, because these plants are correlated with human occupation. The extra-regional taxa, especially Rhododendron, in the mud puddle sediments are significant and strongly suggestive of butterfly migration from higher altitudes. Evergreen elements, along with ferns and fungal remains, in the palynoassemblage are strongly indicative of high rainfall under warm and humid climatic conditions. Thus, the main aim of this observation was to identify the potential of butterfly mud puddle samples and its comparison with other surface pollen traps in order to strengthen the relationship between modern pollen and vegetation in floristically rich areas of Assam, northeast India. The palynodata from the butterfly mud puddle locations is a useful source of palynological observation which should be considered in future palynological research.

Depositional Environment of Mio-Pliocene Siwalik Sedimentary Strata from the Darjeeling Himalayan Foothills, India: A Palynological Approach.

A rich and diverse palynoassemblage recovered from the Churanthi River section (26°53' 59.3" N, 88°34' 17.2" E), Darjeeling foothills Eastern Himalaya, has yielded 87 species assigned to 69 genera. The palynoassemblage is rich in angiosperm taxa (45.63%) followed by gymnosperms (0.45%), pteridophytes (18.49%) and fungal remains (23.88%). Based on their nearest living relatives, a wet evergreen to semi-evergreen forest under a humid tropical to sub-tropical environment during the Mio-Pliocene age has been suggested. A lot of angiosperms such as Palaeosantalaceaepites, Araliaceoipollenites, Malvacearampollis, Zonocostites, Neocouperipollis, Dicolpopollis, Palmidites, Palmaepollenites, isolated salt glands of mangrove plant leaves (Heliospermopsis) and Mediaverrunites type of fungal spores, along with ichnofossils like Planolites, Palaeophycus, Skolithos, Rosselia, Ophiomorpha and Teichichnus associated with rippled mudstone-siltstone suggest an environment strongly influenced by brackish water. Primary sedimentary structures in the associated strata indicate strong wave agitation common in shallow marine setting. Some high elevation components (5.14%) such as Alnipollenites, cf. Corylus (Betulaceae), Juglanspollenites, Engelhardtioipollenites (Juglandaceae), Quercoides, Cupuliferoidaepollenites, Lithocarpus, Castanopsis (Fagaceae), Abietineaepollenites (Pinaceae) represent hinterland vegetation possibly transported to the prograding deltaic coastline by the rivers. Reworked palynotaxa (Striatopodocarpites sp., Striatites sp., Faunipollenites sp., Circumstriatites sp., Crescentipollenites sp., Cuneatisporites sp., Parasaccites sp., Scheuringipollenites sp., Rhizomaspora sp., Marsupipollenites sp., Lophotriletes sp.) of Permian age have also been recorded in the palynoassemblage (11.55%) indicating the abundance of Permian Gondwana strata in the source area.

Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia

Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia). The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation) of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.

Characteristic modern pollen assemblages in relation to vegetation types in the East Khasi Hills, northeast India

ABSTRACTThis paper presents characteristic modern pollen assemblages in relation to various vegetation types from one of the wettest regions of the world. Four characteristic modern pollen assemblages were recorded based on the major pollen taxa recovered from the surface samples. The Pinus–Tsuga–Betula–Quercus–Rhododendron–Chenopodiaceae assemblage was observed in pine forests under cold and wet climate in the region. The broad leaved forests were characterised by the Quercus–Betula–Alnus–Rhododendron–Pinus–Impatiens assemblage. The evergreen forest assemblage Castanopsis–Mesua–Betula–Magnoliaceae–Dipterocarpaceae–Nepenthes was suggestive of a cold and wet climate due to seasonally high rainfall activity. Grassland was identified by the recovery of a Poaceae–Cyperaceae–Asteraceae–Chenopodiaceae–cerealia assemblage in the surface samples under relatively dry climate with seasonal rainfall. The study revealed that the grasslands of East Khasi Hills are not the primary vegetation, but that it is converted from the primary dense forest as evidenced by the recovery of pollen from evergreen and broadleaved taxa in the surface samples. The presence of cerealia in almost all samples strongly indicates human activity in and around the study areas. Ferns, especially Cyathea, Gleichenia and Pyrrosia, in the palynoassemblage were suggestive of wet conditions in the region. Fungal remains such as Meliola, Microthyriaceae and Xylaria along with high organic matter in the palynoassemblage also suggest the same. The thrust of this study was to investigate the characteristic pollen assemblage in the surface samples in relation to the present vegetation of northeast India.

Palynofloral Evidence for PaPalynofloral Evidence for Palaeoecology and Depositional Environment of the Kopili Formation (Late Eocene), Jaintia Hills, Meghalaya

Abstract A rich and diversified palynofloral assemblage has been recovered from the Kopili Formation exposed at 136 km post on Jowai-Badarpur Road, Jaintia Hills, Meghalaya, India. Besides the gymnospermous and angiospermous pollen and pteridophytic spores, the palynofloral assemblage also contains dinoflagellate cysts, fungal remains, bryophytic spores and reworked Gondwana palynofossils in good amount. Based on the distribution and habitat of the extant counterparts of recovered palynofossils, eight plant complexes have been recognized. Most families represented in the assemblage are presently distributed in the tropical to sub-tropical regions indicating almost similar climatic conditions during the deposition of Kopili sediments. The palynofloral assemblage indicates coastal to marine depositional environment with minor oscillations of sea, having fresh water connections with swamps and ponding conditions nearby.

Light microscopy can reveal the consumption of a mixture of psychotropic plant and fungal material in suspicious death

Light microscopical examination of plant and fungal remains in the post mortem gut may be capable of demonstrating the ingestion of unexpected natural psychotropic materials. This is demonstrated here in a case in which a 'shaman' was accused of causing the death of a young man. The deceased had participated in a ceremony which involved the drinking of ayahuasca in order to induce a psychotropic experience. Ayahuasca is an infusion of Banisteriopsis caapi (ayahuasca vine), which produces a monoamine oxidase inhibitor, and one or more additional tropical plants, generally Psychotria viridis (chacruna) which produces dimethyltryptamine (DMT). The monoamine oxidase inhibitor prevents DMT from being broken down in the gut, so enabling its passage into the bloodstream and across the blood/brain barrier. Toxicological tests for DMT demonstrated the presence of this compound in the body. The deceased was reported to be in the habit of using Psilocybe semilanceata (liberty cap). This fungus (popularly called magic mushroom) contains psilocybin which is hydrolysed in the gut to psilocin; this compound mimics a serotonin uptake inhibitor, and also invokes psychotropic experiences. Microscopical examination established that the ileum and colon contained spores of Psilocybe and, in addition, pollen of Cannabis sativa and seeds of Papaver cf. somniferum (opium poppy). Both the plant species yield psychotropic substances. Palynological and mycological analysis of containers from the deceased person's dwelling also yielded abundant trace evidence of pertinent pollen and spores. The police had requested analysis for DMT but there was no screening for other psychotropic substances. Investigators were surprised that a mixture of hallucinogenic materials had been consumed by the deceased. The charge was modified from manslaughter to possession of a ‘Class A’ drug as the deceased had been consuming psychotropic substances not administered by the 'shaman'. Where death involving drugs from plants or fungi is suspected, microscopical examination of samples from the gut can provide a rapid and effective method for assessing, in a temporal context, the presence of ingested materials that may not have been previously suspected. The example presented here also demonstrates the need for caution in interpreting toxicological results where screening for unusual compounds has been limited.

Multi-proxy records of Holocene palaeoenvironmental changes in the Varna Lake area, western Black Sea coast

High-resolution spore-pollen analysis of laminated sediments of newly taken Core-3 (870 cm long) from Varna Lake (northeastern Bulgaria) is combined with multiproxy micropalaeontological analyses of dinoflagellate cysts, acritarchs, and other non-pollen palynomorphs (NPP), including fossil algal and fungal remains. The location of the core is close to several submerged praehistorical sites and the Varna Chalcolithic Necropolis, and permits more precise palaeoecological correlations of obtained results with available archaeological and geochronological data. The established Age vs. Depth Model shows that the formation of the lake started after 7870 cal. BP due to a rise of the Black Sea level, also known as the First Phase of the Vityazevyan Black Sea Transgression. After ca. 94 y, the Second Phase of the Vityazevyan Black Sea Transgression is registered by a major change in the sedimentation and formation of molluscan shell hash layer of Mytilus galloprovincialis that covers the interval 7776 to 6183 cal. BP. Mixed oak and hornbeam forests dominated the vegetation cover during the Atlantic, Subboreal and Subatlantic chronozones of the Holocene. An important change in the forest composition occurs at ca. 5518 cal. BP, when Carpinus betulus reached its maximum spread due to a climate change. The high-resolution geoarchaeological reconstruction of palaeovegetation also reveals the extent of anthropogenic influence in the Varna Lake area, with deforestation and agricultural practice. Two periods of significant presence of pollen from cultivated cereals, and secondary anthropogenic indicators (weeds and ruderals) were identified. According to the available AMS-radiocarbon data, these periods correspond to the Late Eneolithic and Early Bronze Age. The Transitional period without human activities between these two archaeological periods lasted ca. 319 y and coincides with a rise of the Black Sea level, reflected by the increase of euryhaline marine dinoflagelate cysts Lingulodinium machaerophorum and Spiniferites belerius, and acritarchs Cymatiosphaera globulosa and Micrhystridium cf. ariakense during the First Phase of the Kalamitian Black Sea Transgression. The increased values of Corylus coincidently with decrease of Quercus and Ulmus suggest clearance of forests and enlargement of arable areas during the Late Eneolithic. The NPP-record of spores of coprophyllous fungi Cercophora, Sordaria, Podospora and Chaetomium indicates the presence of domestic animals during the Early Bronze Age. The maximum of Alnus, Ulmus, Fraxinus excelsior-type and Fagus pollen at 717 cal. BP suggests an increase of humidity and cooling of climate during the Subatlantic.

Wood decay of Xenoxylon yunnanensis Feng sp. nov. from the Middle Jurassic of Yunnan Province, China

Abstract A permineralised gymnosperm wood, Xenoxylon yunnanensis Feng sp. nov., is described from the Middle Jurassic Shaximiao Formation in Huize County, Yunnan Province, Southwest China. The pycnoxylic wood consists of thick-walled tracheids and thin-walled rays. It is characterised by uniseriate, contiguous, compressed bordered pits on the radial walls of tracheids, and one large simple pit in each cross-field. Growth rings exhibit narrow latewood. The mean sensitivity of analysis of 25 growth rings is 0.2, suggesting that a climate with abundant rainfall and weak seasonality could have prevailed in Yunnan, at least locally, during the Middle Jurassic. The outer portion of the wood is largely decayed, and shows poorly preserved cells lacking details. Decayed tracheids displaying various features, including removal of middle lamellae, separations of secondary walls, presence of thickened corners and appositions, are recognised as cell reactions to fungal activity. Irregularly distributed micro-cavities are formed by complete decomposition of tracheids and rays in the wood. Abundant fungal remains occurring in the wood generally consist of multiple branched hyphae. These fungal hyphae are either confined to individual cell lumens or extend through adjacent cells. Although the probable reproductive structure and typical clamp connection are very rarely observed with few septate hyphae, the affinities of these fungal hyphae are somewhat obscure. Nevertheless, our study sheds light on the palaeoecology of Middle Jurassic terrestrial ecosystems of Southwest China.

A multi-proxy peat study of Holocene vegetation history, bog development, and carbon accumulation on northern Vancouver Island, Pacific coast of Canada

We present a multi-proxy paleoenvironmental study on a 10,400 cal. yr peat sequence from an ombrotrophic bog in coastal British Columbia, Canada. Pollen, non-pollen palynomorph, plant macrofossil, and physicochemical analyses (bulk density, %C, %N, δ13C, and δ15N isotopes) were used to document changes in vegetation, bog development, and carbon and nitrogen accumulation. Pollen assemblages indicate that regional vegetation in the warm, relatively dry early Holocene was mixed coniferous forest with scattered Pseudotsuga menziesii. Herbaceous peat with a C:N of ~28, combined with Nuphar microfossils and relatively high %N, suggests the presence of a herb-dominated peatland with standing water and/or bog pools. Carbon and nitrogen accumulation were at their highest during this early Holocene period at mean rates of 30.6 and 1.2 g/m2/cal. yr, respectively. By 8000 cal. yr BP and under a cooler, wetter climate, northern Vancouver Island supported Tsuga heterophylla rainforest similar to today. Decreasing relative water table, inferred from testate amoebae and fungal remains, facilitated the establishment of a Sphagnum bog by 8000 cal. yr BP with abundant ericaceous shrubs after 5000 cal. yr BP. Temporal variation in carbon accumulation rates corresponds with changes in plant functional types and hydrological conditions: rates were lowest in the early to mid-Holocene during accumulation of Sphagnum peat (7.1 g/m2/cal. yr) and increased in late Holocene ligneous peat (12.4 g/m2/cal. yr). Our multi-proxy approach not only demonstrates the overarching control of climate on bog development and carbon and nitrogen accumulation, with seasonality likely playing a major role, but also highlights the strong influence of autogenic processes at a local scale.

Aptian-Late Cenomanian Fluvio-Lacustrine Lithofacies and Palynomorphs from Mamfe Basin, Southwest Cameroon, West Africa

The sedimentary sequences in the Mamfe Basin are generally thought of as continental (fluvio-lacustrine) in origin. But the wide spread occurrence of salt springs and salt accumulations and in places gypsum, often puts to question the exclusive continentality throughout this basin’s history. The sequences studied portray a wide range of complex lithologies and lithofacies relationships and include basal and intra-formational conglomerates, sandstones, shales, carbonaceous, carbonate and halite facies respectively. All these are well exposed at several outcrop sections distributed all over the basin with some measuring up to and above 30 m in height. Sedimentary structures include: parallel aligned imbricated prismatic pebbles, plannar to trough-cross stratifications, fining upward grain size distribution and thin frequently alternating sandstone-shale beds. Palynological data have been obtained for the first time from the shally and carbonate intervals and integrated with five lithofacies associations, permitting the determination of the ages and paleo environmental reconstruction. The palynomorphs are characterized by pteridophytic spores dominated by Cicatricosisporites sp.,Cyathidites sp. and Deltoidspora sp., pollen grains include gymnosperms dominated by Classopollis annulatus and Classopollis todosus and angiosperms represented by Retitricolpites sp. and Retimoncolpites sp., fungal remains include some hyphae and Fusiformisporites sp. Only a few dinoflagellate cysts dominantly Spiniferites were encountered at Nfaitok outcrop, suggesting a proximal sea water influence. A fluvial, lacustrine-deltaic and an anoxic deep bottom lake setting sub-environments were reconstructed with no marine strata encountered. The brines are here suggested to have originated from sea water splay over a barrier and complimented by the chemistry of the drained surrounding country rocks. The palynomorph assemblage suggests an Aptian-Turonian age for the studied sequences and a chronostratigraphic sequence in which the Nfaitok and Satom Bridge units are both Late Cenomanian-Turonian (lateral equivalents of each other) are younger and overlie the Aptian-Early-Cenomanian Okoyong sandstone unit.

Evidence of deterioration in phytodiversity of Itanagar Wildlife Sanctuary, Arunachal Pradesh, India based on palynological evidence

The pollen–spore assemblage and their preservation status study based on 25 surface samples from different sites of Itanagar Wildlife Sanctuary, Arunachal Pradesh is documented. The survey was based on 25 surface samples from different sites of the sanctuary with a view to assess actual status of pollen preservation. The pollen assemblage depicts predominance of the nonarboreals over arboreals which do not fully match the present vegetation of the sanctuary. However, the occurrence and relative abundance of both deciduous and wet evergreen forest complex though in low frequency are of great significance towards its existence. Arecaceae pollen probably belongs to Arenga and Livistona despite their absence in surrounding vegetation. The presence of cerealia and other cultural pollen, viz. Chenopodiaceae and Xanthium are suggestive of the anthropogenic activity in and around the study area. The enhanced fern allies especially Osmunda, Cheilanthes, Gleichenia, Dipteris and Pteris pentagyna are supposed to be of subtropical–temperate in origin coupled with fungal complex (Glomus, Xylaria and Microthyriaceae) indicate humid depositional environment in the basin. Prevalence of rich organic matters festooned with fungal remains may be attributed due to relatively higher rates of weathering and erosion of the hinterland influenced by enhanced SW monsoon during the time of deposition. The incidence of degraded palynomorphs indicates aerobic microbial diagenesis of rich organic debris during sedimentation. The overall palynological result hints a deteriorating scenario of wildlife sanctuaries and associated region in recent times.

Modern Pollen Record on Bat Guano Deposit from Siju Cave and its Implication to Palaeoecological Study in South Garo Hills of Meghalaya, India

Meghalaya is well known for its rich tropical biodiversity and numerous natural caves. The Siju Cave of Meghalaya, also known as cave of the bat, is among the longest caves on the Indian subcontinent. The palynological study of fifty bat-guano samples from Siju Cave and of thirty surface soil and moss cushion from the area immediate surrounding the cave reflects the close similarity between the modern pollen and vegetation in the region in the two areas sampled. The resulting palynodata comprise mainly the native flora, dominated by riparian taxa like Duabanga, Syzygium, Careya, and Ficus, along with evergreen and deciduous elements in the region. The evergreen taxa Mesua, Elaeocarpus ,a ndGarcinia, along with Impatiens, reflect the high precipitation in the region. The climate of the region and the vegetation are strongly influenced by the Simsang River, and the heavy rainfall results in the dominance of riparian taxa and other high-rainfall indicator taxa. The occurrence of pollen from Nepenthes khasiana ,a n endemic and endangered plant of Meghalaya, in bat guano is significant and may be due to its insectivorous and entomophilous nature. However, medicinal plants like Swertia chirata, Cinchona, and Rauvolfia are not encountered in the bat-guano sediments, despite their luxuriant growth around the cave, and these species could be avoided by the insects due to their alkaloid contain and bitter taste. The presence of highland taxa such as Pinus, Abies, Picea, and Larix in the bat guano deposit is significant and suggestive of high winds from higher altitudes, or the pollen may be introduced by the return of migratory Siberian birds during winter to the nearby Siju wildlife and bird sanctuary. The recovery of cerealia along with Areca catechu and Citrus pollen indicate the human activity in the region. The abundance of fungal remains, namely Meliola, Glomus, and Microthyriaceae along with degraded palynomorphs are suggestive of strong microbial activity under warm and humid conditions during sedimentation in the region. The main objective of this study is to identify the potential of bat guano for palaeoecological research and as supportive data for surface and sedimentary soil profiles in the South Garo Hills of Meghalaya. The palynodata from the bat guano of the Siju Cave provides a useful source for palaeoecological information for the South Garo Hills, where intensive natural and human-caused forest fires, heavy rainfall, and soil erosion occur every year and there is a relative scarcity of the lake, wetland, and swamp habitats that normally preserve pollen.

Leaf cuticular morphology of some angiosperm taxa from the Siwalik sediments (middle Miocene to lower Pleistocene) of Arunachal Pradesh, eastern Himalaya: Systematic and palaeoclimatic implications

Seven fossil leaves with cuticle described here were collected from the lower, middle and upper strata of Siwalik (middle Miocene–lower Pleistocene) sediments of Arunachal Pradesh, India. A detailed comparison of the cuticular analysis of the fossils and their living relatives indicate that these fossil species belong to Dysoxylum raptiensis, Macaranga cf. denticulata, Calophyllum suraikholensis, Combretum prechinense, Actinodaphne palaeoangustifolia, Shorea siwalika and Dipterocarpus koilabasensis. Among these fossil species C. prechinense has been described as a new species. The present day distribution of the modern equivalent taxa of the fossils, structural features and the micro-morphological features of the fossil leaves together with epiphyllous fungal remains collectively indicate the prevalence of a warm humid tropical climate in this area during Siwalik sedimentation. The cuticular micro-morphological features help to confirm the identification of their leaf compressions to the species level and are clearly indicative of mesophytic ecological conditions that reflect a tropical climate with high precipitation. This is the first time Cenozoic fossil leaves of Dysoxylum, Macaranga, Calophyllum, Combretum, Actinodaphne, Shorea and Dipterocarpus are described using the micromorphology of their epidermis.

Nouvelles données paléoécologiques issues des mares intra-forestières du plateau de prémery (Bourgogne, France)

Les mares intra-forestieres ou « mardelles » situees en foret de Premery sur le plateau nivernais (Bourgogne, France) ont un potentiel paleoecologique qui a deja ete exploite dans les annees 60. De nouvelles analyses, alliant pollens, spores et autres microfossiles non-polliniques (principalement algues et spores fongiques), realisees sur deux sequences, offrent des enregistrements complementaires pour documenter le contexte de formation du comblement de ces depressions fermees, ainsi que les evolutions de la vegetation sur le plateau nivernais. Les deux carottes sont en partie chronologiquement complementaires. La premiere concerne la periode tardiglaciaire ainsi que le debut de l’Holocene (entre environ 16 000 et 10 000 ans), mais elle est plus difficilement exploitable pour l’Holocene moyen et recent, a cause de plusieurs hiatus sedimentaires. La seconde sequence ne documente que la fin de la periode tardiglaciaire (Dryas recent), mais en revanche, couvre l’Holocene de facon continue. Du point de vue de l’impact anthropique, la perception des activites agro-pastorales est extremement faible et sporadique dans le secteur des mardelles durant la Prehistoire et l’Age du Bronze (de 5 000 a 800 ans avant notre ere). Ensuite, malgre plusieurs phases de deforestation des chenaie-hetraies a l’Age du fer (800-50 ans avant notre ere), au Moyen Age classique (autour de l’an Mil) et a l’Epoque moderne, le couvert forestier demeure dominant, et les indices polliniques et fongiques de proximite des activites humaines ne sont enregistres qu’entre les xvie et xixe siecles, sur une seule des deux sequences. Toutefois, on peut evoquer l’exploitation de la foret a d’autres fins que la conquete d’espaces agropastoraux : bois de feu, bois d’œuvre, artisanat et paleo-industries...Si ces depressions fermees ont suivi des schemas d’evolution comparables de la mare en eau libre a la micro-tourbiere au Tardiglaciaire et au debut de l’Holocene, leur histoire holocene differe ensuite. Ces differences montrent l’importance de la variabilite des fonctionnements des bassins versants ou chacune d’entre elles se developpe dans sa dynamique de comblement, et soulignent la valeur tres locale des enregistrements paleoecologiques qu’elle renferme.

Vegetation vis á vis climate change around Bhogdoi swamp in lower Brahmaputra flood plain of Assam, Northeast India since Late Holocene

Pollen records from 1.8 m deep sedimentary profile cored from Bhogdoi swamp, Kamrup District, lower Brahmaputra flood plain of Assam, Northeast India have revealed enrichment of tropical mixed deciduous forest elements including Shorea robusta, Syzygium cumini, Dillenia pentagyna and Acacia catechu indicating warm and humid climatic regime during 3,795–2,530 years BP. Subsequently during 2,530–680 years BP relative increment in proliferation of tropical mixed deciduous elements namely Lagerstroemia parviflora, Lannea coromandelica, Terminalia bellirica, Sapotaceae and Emblica officinalis occurred resulting into final settlement of tropical mixed deciduous forest under increased warm and humid climatic regime attributable to active Southwest Monsoon. However, from 680 years BP onward gradual deterioration of mixed deciduous forest occurred as evidenced by sudden decline in Sal and its associates under warm and relatively drier climate. Drastic increment in Melastoma, Ziziphus and Areca implying forest clearance at this phase. The occurrence of degraded pollen–spore along with adequate fungal remains especially Xylaria, Diplodia, Nigrospora and Microthyriaceous fruiting body is suggestive of aerobic microbial digenesis of rich organic debris during sedimentation.

Epiphyllous fungi from the Oligocene shallowmarine deposits of the Krabbedalen Formation, Kap Brewster, central East Greenland

ABSTRACT Fructifications of epiphyllous fungi were encountered during palynological investigation of the Lower Oligocene shallow-marine deposits of the Krabbedalen Formation at the Savoia Halvø, Kap Brewster, central East Greenland. Six fossil taxa from the family Microthyriaceae (Phragmothyrites kangukensis Kalgutkar, Phragmothyrites sp., Plochmopeltinites sp., Trichothyrites cf. ostiolatus (Cookson) Kalgutkar & Jansonius, Trichothyrites sp. 1, and Trichothyrites sp. 2) and one incertae sedis fungal remain are reported. Fungal remains from the Krabbedalen Formation represent the youngest, Oligocene occurrence of the epiphyllous fungi in the Palaeogene of the Arctic. The presence of epiphyllous, microthyriaceous fungi in low quantities and in low taxonomical diversity points to a humid and not necessarily warm climate, which is corroborated by data obtained from the analysis of microscopic plant remains.

Palynology, Palaeoecology and Palaeodepositional Environment of Eocene Lignites and Associated Sediments from Matanomadh Mine, Kutch Basin, Western India

Abstract: Extensive Cenozoic lignite-bearing sediments in the western part of Kutch, western India provide a unique opportunity to study the floral diversity at a crucial time of early Eocene Climatic Optimum (EECO). Rock samples representing a lignite-bearing sequence from the open cast mine at Matanomadh, Gujarat, western India were collected to study the palynofloral composition and to interpret the palaeoclimate and environment of deposition. The sequence mainly composed of lignites, shales and calcareous mudstones yielded rich assemblage consists of pteridophytic spores (7 genera, 10 species), angiosperm pollens (20 genera, 26 species), fungal remains (14 genera, 16 species) and dinoflagellate cysts. The palynofloral assemblage is marked with dominance of angiospermic pollen, particularly those having affinity with the family Arecaceae. Occurrence of fungal remains in high abundance is also noticed. Based on palynomorph contents, the studied sequence is divisible into two palynozones. It is inferred that lower part of the sequences was deposited in a near-shore environment with intermittent marine incursions whereas the depositional regime of upper part was shallow marine. The climate is found to be tropical-subtropical, humid with heavy precipitation during the deposition of Matanomadh lignite-bearing sequence.

Cinnabar-Preserved Bone Structures from Primary Osteogenesis and Fungal Signatures in Ancient Human Remains

The Red Queen remains (700 A.C.) found at Palenque, México, are examples of cinnabar (HgS) application to royal remains during pre-Hispanic times. The Red Queen remains are those of a ca. 30–35-yr-old female and present a striking similarity to the remains of another Mayan woman found at Copan, Honduras. Thus, covering the remains of royal women with HgS may have been a common practice in the Mayan civilization. High resolution microdiffraction and microscopic analysis of the Red Queen remains showed the presence of nanotubular organic minerals comparable in composition and molecular dimensions to collagen fibrils, and in spatial ordering to collagen fiber networks. Fungal structures are rare in the geological record because of poor preservation potential. Micrographs revealed the preservation of fungal signatures, with morphology comparable to parasitic fungal-coral matrix associations, consistent with the idea that fungal remains can be preserved in environments which contain high Hg concentrations. The well-preserved signatures of fungus-animal interactions and primary osteogenesis in the Red Queen remains are attributed to the long-term antibacterial activity of HgS and the association of sulfur components with nanotubular structures.

Palynostratigraphy and depositional environment of Vastan Lignite Mine (Early Eocene), Gujarat, western India

Early Eocene sedimentary successions of south Asia, are marked by the development of extensive fossil-bearing, lignite-rich sediments prior to the collision of India with Asia and provide data on contemporary equatorial faunal and vegetational assemblages. One such productive locality in western India is the Vastan Lignite Mine representing approximately a 54–52 Ma sequence dated by the presence of benthic zone marker species, Nummulites burdigalensis burdigalensis. The present study on Vastan Lignite Mine succession is based on the spore-pollen and dinoflagellate cyst assemblages and documents contemporary vegetational changes. 86 genera and 105 species belonging to algal remains (including dinoflagellate cysts), fungal remains, pteridophytic spores and angiospermous pollen grains have been recorded. On the basis of first appearance, acme and decline of palynotaxa, three cenozones have been recognized and broadly reflect changing palaeodepositional environments. These are in ascending stratigraphic order (i) Proxapertites Spp. Cenozone, (ii) Operculodinium centrocarpum Cenozone and (iii) Spinizonocolpites Spp. Cenozone. The basal sequence is lagoonal, palm-dominated and overlain by more open marine conditions with dinoflagellate cysts and at the top, mangrove elements are dominant. The succession has also provided a unique record of fish, lizards, snakes, and mammals.