bluuebunny/crossref_metadata_2025 huggingface dataset:
Changing pattern of vegetation in the intermontane basin of Kashmir since 4 Ma: a palynological approach
Authors: Gupta H.P.
Published: September 2022

The Upper Karewas are devoid of biomass potential and hence no palynostratigraphy could be established. In contrast, Lower Karewas are both quantitatively and qualitatively rich in biota. The major areas of study include Dubjan, Hirpur, Krachipathra, Ningle Nullah, Laredura, Liddarmarg, Butapathri, Wapjan, etc. Dubjan, supposedly the basal part of the Karewa sequence, overlies unconformably the Panjal volcanics and Hirpur overlies the Dubjan. Recent palaeomagnetic studies suggest that these sediments span late Gilbert to middle Matuyama magnetic polarity ranging in age between 3.5 to 2.0 Ma. Wapjan is the uppermost pan of the Lower Karewa and falls between late Matuyama to early Bruhnes ranging in age between 0.75 to 0.70 Ma.

Palynological and palaeobotanical investigations carried over a large number of exposures have revealed that there is no unanimity in vegetation all through the Karewa deposits, instead, a variety of vegetation types has been recorded in time and space indicating their development under different circumstances. The vegetation met here varies from typical subtropical to desertic alpine type. The climate has not been static for a long period rather reciprocity in the climate has been recorded which has been deciphered from vegetal signatures left by the nature. Post-glacial sediments from the lake basin in the valley have also been investigated, which reveal three-fold vegetational development reflecting on three-fold climatic evolution.
Last 20,000 years of climatic change
Authors: Agarwal D.P.
Published: September 2022

Recent evidence, especially from continental Asia, shows that there are marked latitudinal differences in global climatic changes. From India, we now have new evidence from Kashmir, Rajasthan and the Arabian Sea which shows that in the north (35°- 40° N latitude) warming had started c. 20,000 yrs BP in Kashmir, Ladakh and Nepal when in higher latitudes it was still the Last Glacial Maximum (LGM). At c. 18 Kyr, Butapathri (Kashmir) bogs show emergence of thermophilous plants like Alnus, Juglans, Carpinus at the cost of conifers. A palaeosol on the loess profile of Kashmir is datable to c. 18 Kyr which again shows climatic amelioration. Organic matter from this palaeosol gives δ 13C values of about -24‰ indicating that it was derived from C3 type of vegetation. Presence of an Upper Palaeolithic culture at this time, in Kashmir, again confirms a period of climatic amelioration.

From Ladakh, Bhattacharya has inferred climatic amelioration from the higher percentage of Juniper during 20- 20 Kyr period. Similarly in Nepal, a climatic amelioration is indicated. In Rajasthan, c. 18 Kyr is a period of aridity. Maximum sand building activity is TL dated by Singhvi to c. 14 Kyr and just preceeds the strengthening of the monsoon in c. 13 Kyr. Upwelling at c. 13 Kyr in the Arabian Sea has been reported by Anderson et at. (1990) and the French group has shown a similar evidence of monsoon strengthening at c. 13 Kyr based on pollen evidence fom African lakes. Unfortunately, we have only one 14C date from Butapathri which shows that at c. 10 Kyr the cooler oscillation was on its way out and warming had gradually started. We need more closely spaced 14C dates for such profiles. In the Arabian Sea cores the spike at c. 18 Kyr of freshwater (low salinity, low δ 18O, high δ 13C) has been interpreted variously as due to the strengthening of NE monsoon or due to Tibetan ice melt. The role of Tibet in climate forcing is being emphasized by multiple new data. It will be relevant to know what was happening in peninsular India during this period.
Rock building Cretaceous - Tertiary algae from India - an ecological perspective
Authors: Rajanikanth A.
Published: September 2022

Fossil benthonic photosynthetic algae capable of calcification contributed to the formation of Indian Cretaceous-Tertiary carbonate deposits. A comparative assessment of different marine calcareous algal assemblages known from various sedimentary basins and their ecological requirements have been highlighted. A comprehensive synthesis and retrospect of research on calcareous algae demonstrate extensive growth of green and red algae during Cretaceous-Tertiary times in India. The calcareous blue-green algae are feebly represented in the Cretaceous deposits and not recorded from the Tertiary deposits. Various ecological factors determined the distribution of different calcareous algal groups. An apparent extinction of calcareous algae is attributed to gaps in our knowledge and evolutionary changes.
Himalayan coals: their nature, composition, formation and rank
Authors: Anand-Prakash
Published: September 2022

The results of maceral, microlithotype and reflectance analyses, so far carried out on the Palaeozoic (Permian) and Tertiary coals of Himalaya, have been presented along with the details of geological and chemical (proximate) studies. The Permian coals, enclosed in the sediments dispersed as thrust slices in the eastern Himalaya, are characterized by their high rank and the dominance of the maceral vitrinite. In general, these coals are classified as semianthracite, except for the Bhutan coals which are of low rank and high volatile bituminous in nature. Almost all the macerals contain fairly high amount of mineral matter. Finely disseminated argillaceous matter is the most common mineral suite present in the coals followed by carbonates and iron sulphide (pyrite). In most of the cases, the mineral matter is present as infillings in numerous sets of fissures which traverses the coals. These infillings seem to have been developed during the tectonic activity and represent secondary minerals impregnated in various macerals. Often the presence of high amount of mineral matter has greatly reduced the quality of coal. Besides, the marine animal fossil-bearing mineral concretions (coal balls) have indicated that these coals were formed in a series of lagoons under the influence of marine conditions.

The Upper Tertiary coals, associated with the Tipam sediments in the eastern Himalaya, occur as small lenses, very thin impersistent seams and pockets which are characterized by the dominance of maceral vitrinite. It is generally represented by the structured variety (telinite). In general, the cellular structures indicate that these coals have been formed by the burial of wood logs in the fluvial sediments. An important feature of telinite is the presence of folded tissues which attain prominence in the coals occurring closer to the main boundary faults. The coals in this area exhibit lignite-bituminous stage in rank and are comparable to the Mesozoic coals in peninsular India. This stage in rank has been possible mainly due to the tectonic disturbances.

The Lower Tertiary coals of Jammu area are the only economically workable deposits in the Himalayas. These are associated with the beds containing marine animal remains. This indicates that coal formation took place under near-shore environment. These coals are comparable to the Permian coals of the eastern Himalayas. They are also rich in maceral vitrinite and semianthracitic in rank. Such a high rank of these Tertiary coals may be attributed to the effect of tectonic movements in the Himalayan areas.
A consideration of the evolutionary trends in the blue-green algae with palaeontological evidences
Authors: Desikachary T.V.
Published: September 2022

Blue-green algae are known right from the Precambrian to Recent. Evolutionary concepts have largely been based on comparative morphology of extant forms as revealed by culture studies. Broadly speaking two trends came into vague: (i) the ‘retrogressive’ concept elucidated by Geitler (1925), and (ii) the ‘progressive’ one laid out well by Fritsch (1942). Because relatively few fossil blue-green algae were then known, palaeobotanical evidence played only a small part in these approaches. Korde (1971) was the first to present a consolidate picture of the phylogenetic trends as revealed by fossils. Evidences that one looks for among the fossils relate to the origin of the filamentous condition, appearance of the heterocysts and the origin of heterotrichous habit and true branching. Most of the trends seen in the present day filamentous organization appeared in the Precambrian. Trichomatous condition developed in a major way in the Precambrian itself. The first uncontroverted record of a heterocyst apparently comes from Cambrian strata. The hormogone and spore types appeared earlier than the heterocyst. Records of heterocystous forms seem to point to an evolution of heterocystous types later. These forms parallel the homocystous morphotypes known earlier. True branching types seem to have come much later than the Cambrian. The fossil record of these forms seems to clearly support a ‘progressive’ type of evolution in two phyletic lines, the homocystous/aheterocystous line preceding the heterocystous line. This evidence clearly supports Elenkin’s concept of parallel evolution but not his ‘retrogressive’ projections. Reduction may be relevant only in smaller clines. The blue-green algae as a whole seem to be a conservative group where major developments occurred very early before the end of Proterozoic and do not exhibit any great degree or rate of change during later periods as do many other groups of biota. More work on these fossils is the need especially in the Indian subcontinent.
Taper of some Early Palaeozoic plants
Authors: Niklas Karl J. , Banks Harlan P.
Published: September 2022

A new method was used to measure the degree of taper of Devonian plant axes: the width w of each compression fossil (measured at distance x along the length L of each axis) was normalized with respect to the basal width w0 of each axis w/w0 and plotted against normalized axial length x/L. the degree of taper was taken as the slope m of the simple linear regression of (w/w0)3 versus x/L. Comparisons among m showed that different levels of branching on some specimens were statistically distinguishable, as were sterile and fertile axes from the same specimen. In contrast, sterile axes of similar rank in the hierarchy of branching from different species were found to have statistically indistinguishable degrees of taper. The degree of axial taper was observed to slightly increase over geological time, although the limited number of taxa examined make any definite conclusion unwise. Provided fragmented plant axes can be identified as belonging to a particular species, the allometry of axial taper could provide a useful method distinguishing different levels of branching in a plant body. Additionally, because the method used to quantity the magnitude of axial taper was derived from engineering theory, it may ultimately provide quantitative insight into evolutionary changes of the “mechanical design” of columnar and lateral cantilevered axes.
Origin and evolution of lycopods
Authors: Ramanujam C.G.K.
Published: September 2022

The lycopods are known from as early as Sieginean Stage of the Lower Devonian. Lower and Middle Devonian lycopods were all herbaceous. Arborescent taxa appeared by Upper Devonian (e.g., Cyclostigma and Lepidosigillaria). The microphyllous foliage of lycopods seem to have originated from enations as well as telomic trusses. The lycopods attained peak of their evolution during the Upper Carboniferous. Towards the close of the Carboniferous and dawn of the Permian, with gradual dwindling and disappearance of swamps, the lepidodendrids suffered drastic decline numerically and phytogeographically. General aridity of the Triassic resulted in acute dwarfing as evidenced by Pleuromeia. This trend continued further resulting in the highly telescoped Nathorstiana during the Cretaceous. The earlier lycopods were homosporous; heterospory appeared by Upper Devonian. Heterospory ran rampant in the Lepidodendrales. The ultimate in heterospory and the approach to seed habit could be witnessed in Lepidocarpon. Four discrete types of strobilus organization could be recognized by the Lower Carboniferous, viz, 1. Lepidostrobus type, 2. Mazocarpon type, 3. Achlamydocarpon type, and 4. Lepidocarpon type. Recent studies point towards the origin of lycopods along two different pathways, with both Zosterophyllopsida and Rhyniopsida representing the progenitors. All available evidence shows that Lycopsida constitutes a ‘Blind Alley’ in the evolution of vascular plants.
The role of vertebrate herbivory in the evolution of land plants
Authors: Tiffney Bruce H.
Published: September 2022

Land plants have evolved in the selective context of their surrounding environment. Climate has long been discussed as a selective force, but the effects of vertebrate herbivores may also be significant. Four phases of vertebrate herbivory may be recognized in the fossil record. The Silurian-Late Carboniferous apparently lacks vertebrate herbivores. The Early Permian-Late Triassic is dominated by low-feeding therapsids. The Late Triassic-K/T boundary is dominated by large archosaurian herbivores. The Tertiary-Present is dominated by small birds and mammals. Recognition of these changing forces of vertebrate herbivory will aid in understanding the evolution of vascular plants.
The glossopterid group of plants in an evolutionary perspective
Authors: Maheshwari H.K , Srivastava A.K.
Published: September 2022

The glossopterid group of plants was the most dominant constituent of the Permian vegetation of the Gondwana Supercontinent. During last one hundred and fifty odd years, a staggering amount of data has accrued on leaves, wood, root, fructifications, seed and pollen that possibly belonged to this group. Evolutionary pathways with the group, however, are yet little understood.

Considering the venation and epidermal features of the leaves, two patterns are unfolded; one with leaves having dichotomizing, almost parallel veins and stomata in linear rows, the other with dichotomising and anastomosing veins and stomata irregularly distributed in the mesh areas.

Oldest glossopterid fructifications, viz., Arberia/Dolianitia show a certain resemblance with the cordaitalean fructifications, thus suggesting that group of plants with Cordaites/Noeggerathiopsis/Pantophyllum type leaf and Arberia/Dolianitia type infructescence probably was the precursor of the glossopterids. Overall evidence suggests the development of this group of plants along two successive lineages.
Morphologicals evolution of pteridophytic spores in relation to free-floating environment
Authors: Kar R.K.
Published: September 2022

The free-floating ferns are mostly herbaceous with a trilete mark on the spores. They first evolved in the Early Cretaceous, radiated in the Late Cretaceous and except for Azolla and Salvinia, all of them died out by the Late-Maestrichtian. The common genera are: Arecellites, Molaspora, Balmaeisporites, Ariadnaesporites, Glomerisporites, Parazolla, Azollopsis, Azolla and Salvini. The morphological evolution and adaptation of these genera in relation to the free floating environment is discussed.
Chemodynamics of insect-plant interactions
Authors: Ananthakrishnan T. N.
Published: September 2022

Instances of coevolutionary adaptations in insect-plant interactions are discussed and overall analysis of the chemical ecological basis of host plant suitability and resistance has been attempted including the implications of the impact of volatiles in tritrophic interactions.
Beetle pollination of two species of Zamia: evolutionary and ecological considerations
Authors: Norswg Knut J. , Fawcen Priscilla K. S. , Vovides Andrew P.
Published: September 2022

Two species of cycads in Florida are invariably pollinated by beetles. The native Florida Zamia pumila L. is pollinated by a snout weevil, Rhopalotria slossoni Schaeffer, and a clavicorn beetle, Pharaxonotha zamiae Blake. An introduced cycad, Z. furfuracea L. fil., is pollinated by the snout weevil, R. mollis Sharp, apparently introduced from Mexico along with its host. Observations and experiment show that zamias are dependent upon pollinating beetles for their reproduction, and, in turn, the pollinating insects are dependent upon the cycads for brood places, food and shelter. The two cycads have evolved similar “rewards” which function as pollinator attractants. The importance of these coevolutionary inter-relationship for the ecology and conservation of these cycad species is unquestionable. Neither the insects nor the cycads are separately capable of long term survival in nature, and unless both are protected and conserved, wild populations of Zamia are in jeopardy.
Vesicular-arbuscular mycorrhiza-an evolutionary approach
Authors: Bagyaraj D.J. , Ravindra T. Padmavathi
Published: September 2022

Vesicular arbuscular mycorrhizal (VAM) fungi forming mutuanstic symbiosis with roots of higher plants are present in soil throughout the world. This suggests that VAM fungi disseminated intercontinentally prior to continental drift of the supercontinent Gondwana. The first mycorrhizal symbiosis appears to have occurred early in geological time, as evidenced by their presence in fossil soil and roots. Evidences available to date suggest that VAM fungi co-evolved with land plants. The ability of the host and fungus to maintain the association depend on favourable gene combinations in both partners. Differences in morphology and development of spores of different VAM fungi reflect independent evolution from a number of distinct points of origin. The centre of evolution of VAM fungi appears to be the tropics.
Chemical evolution within the Asteridae
Authors: Daniel M. , Sabnis S. D.
Published: September 2022

Chemical evolutionary pathways operating in the subclass Asteridae have been critically assessed. The different groups of plants are found to experiment with the various plant products such as alkaloids, cardiac glycosides, tannins, volatile oils, quinones and iridoids. Compounds which help plants to combat pathogens, discourage herbivores and act as allelochemics are found to provide a selective advantage to those individuals that possess them. Compounds providing little or no selective advantage are discarded. Trends in the chemical evolution of Asteridae are (i) reduction/elimination of alkaloids, flavonols and proanthocyanidins/tannins, (ii) introduction and further methoxylation of 6-deoxy and 6-oxyflavones, (iii) introduction of iridoids especially aucubins, (iv) development of volatile oils rich in sesquiterpenes, and (v) increased reliability on quinones as antimicrobials and allilochemics. The advanced groups of Asteridae possess a specific assortment of antimicrobials, bitter substances and allelochemics. The classification within the Asteridae is examined in the light of these trends.
Taphonomic considerations for plant evolutionary investigations
Authors: Gastaldo Robert A.
Published: September 2022

Taphonomic processes play the underlying role in the characteristics of fossil plant assemblages. Their influence on this data set, from which we interpret evolutionary trends within lineages and clades, often is not considered or taken into account. Examples are provided to illustrate the effects that plant life strategy, environments and ecological associations, original biochemical constituents, and the nature of depositional regimes have on plant part representation in subfossil and fossil assemblages. It is recommended that fossil assemblages be evaluated within depositional and sedimentological context before the data set is utilized for higher order synthetic investigations.
Structure and floristics of Cretaceous vegetation of southern Gondwana: implications for angiosperm biogeography
Authors: Dettmann M.E.
Published: September 2022

A review of palaeobotanical/palynological data reveals that the vegetation of southern Gondwana was regionalised throughout the Cretaceous. Open forests of high productivity occurred in high southern latitudes whereas woodlands, heathlands and closed forests vegetated mid-latitudinal areas. Angiosperms first entered the region during Barremian-Aptian times from source areas in northern Gondwana. Early immigrants to the Australian-Antarctic assembly were of magnoliid stock, and migration routes involved southern South America. Early angiosperms in India also included non-magnoliid taxa which may have utilised an African/Madagascar corridor. Non-magnoliid angiosperms spread to the Austro-Antarctic landmass during the Albian, some 5-10 Ma after India was isolated from the southern Gondwanan assembly. For the remainder of the Cretaceous southern South America and the Antarctic Peninsula served as an exchange corridor for angiosperms between northern and southern Gondwana. This area was also the cradle of Nothofagus, whereas diametrically opposed land adjacent to the embryonic Southern Ocean was a differentiation centre for the Proteaceae. Angiosperm migration was step wise, and regulated by changing environmental circumstances associated with tectonic/volcanic activity and opening and enlargement of the southern oceans.
Liptinite macerals in Singrauli coals, India: their characterization and assessment
Authors: Misra Basant K. , Singh B.D.
Published: September 2022

The record of liptinite macerals in Indian Permian coals has been uniformly quite low under normal reflected light. In fact, high inherent clastic minerals intimately associated with liptinite macerals in these coals tends to mask them, at times, completely, obstructing identification and for this reason they are considered to be poor in liptinite content. Petrographic investigations carried out on Early Permian Turra coal seam and Late Permian Jhingurdah coal seam of Singrauli Coalfield, under blue light excitation, recorded appreciably high amounts of liptinite macerals (13-57% on mineral matter-free basis) as against maximum up to 19 per cent (m.m.f basis) under normal reflected light. The liptinite macerals in these coals are formed chiefly by sporinite (7-40%) and liptodetrinite (1-16%). Cutinite, suberinite, resinite, alginate, exsudatinite and fluorinate are the other macerals of liptinite group together occurring in only subordinate amounts.

The coals of the Turra seam associated with Barakar Formation have relatively higher liptinite content than that of the Jhingurdah seam of Raniganj Formation. Such high concentration of sporinite has not been reported so far from the Indian Permian coals. The increase in liptinite/sporinite content coincides with increase in mineral matter content in many instances, i.e., dull bands normally have high liptinite content. The sporinite concentration in dull coal bands of the Permian coal seams mark the presence of semi-cannel or cannel coal bands.
New angiosperm pollen from subsurface Early Palaeogene sediments of Barmer District, Rajasthan, India
Authors: Tripathi S.K.M.
Published: September 2022

Two new monosulcate pollen genera, viz., Kapurdipollenites and Retiverrumonosulcites are identified from the subsurface Paleogene sediments near Kapurdi and Jalipa, Barmer District, Rajasthan. Kapurdipollenites is a zonisulcate pollen having verrucate, baculate or gemmate exine. Retiverrumonosulcites is monosulcate with verrucate or clavate exine. These pollens show affinity with those found in some members of Arecaceae.
37th Professor sir AC. Seward Memorial Lecture: Links with the past in the plant world: cuticles as recorders of diversity, kerogen formation and palaeoatmospheric CO2 level
Authors: Visscher H.
Published: September 2022

The study and interpretation of plant cuticles may lead to the establishment of three important (taxonomic, biochemical, physiological) links with the past in the plant world; (1) Cuticles reflect characteristic patterns of epidermal cell organization; on the basis of cuticle analysis natural plant genera and families can be established as a necessary taxonomic background for recognizing past episodes of biodiversity change. (2) Cuticles have a high fossilization potential, due to the presence of resistant biopolymers in the cuticular matrix; chemical analysis of fossil and present-day cuticles can help to clarify interrelationship between extant biomass, kerogen and fossil fuels (3) Cuticles bear the plant’s stomata, essential for photosynthesis; stomatal frequencies are dependent on ambient CO2 concentration, so that calculation of stomatal indices has the potential of determining palaeoatmospheric CO2-levels with the time-scale of the last 10 million years.
A tribute to Professor Ove Arbo Hoeg (1898-1993)
Authors: Tiwari R.S.
Published: September 2022

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Occurrence of endosporulating cyanobacteria in the Lower Bhander Limestone Formation, Bhander Group exposed around Narsingharh, Madhya Pradesh
Authors: Maithy P.K. , Babu Rupendra
Published: September 2022

Endosporulating cyanobacterium Sphaerocongregus is reported for the first time from the cherty hand of the Lower Bhander Limestone Formation. Bhander Group exposed around Narsingharh in Damoh District, Madhya Pradesh. Individual colonies are globose and contain closely packed globular cells. The cells get arranged in the form of a loose colony after the dissolution of the encircling organic sheath. Globular colonies and the encircled cells can be distinctly discriminated into two distinct groups due to their distinct sizes. Globular colonies are clumped together to form either globose mass or linear chain. It is suggested that endosporulation of the algae was due to stressed habitat.
The origin and initial radiation of angiosperms In relation to anthophytes
Authors: Shields Oakley
Published: September 2022

Autapomorphics indicate the angiosperms form a monophyletic group. Analysis of Aptian-Cenomanian macrofossils establishes that Chloranthaceae holds a central position in the initial radiation of dicots. While Palmae was basal to monocot initial radiation in the Maastrichtian. By tracing their fossil pollen back in time, two lines probably arose from two different species of Monocrinopollis (Crinopolles Group) in the Norian (Upper Triassic) The Crinopolles Group were extinct angiosperms that evolved directly from Steevesipollenites (Gnetales). The origin and initial radiation of angiosperms occurred in North America under stress habitat conditions. Glossopteridales, Caytoniales and Bennettitales display extreme convergent tendencies to angiosperms, while Gnetales similarities to angiosperms are more numerous and fundamental. Gnetales-angiosperms and Bennettitales-Pentoxylales evolved as two distinct lines of anthophytes. Bennettitales arose from Gangamopteris (Glossopteirdales) in the Lower Permian of South Africa, while Gnetales evolved either from Bennettitales or Glossopteridales at that time, also in South Africa.
Palynostratigraphical studies on subsurface Tertiary sediments in Upper Assam Basin, India
Authors: Kar R.K. , Handique G K. , Kalita C.K. , Mandal J. , Sarkar Samir , Kumar Madhav , Gupta Asha
Published: September 2022

The present paper incorporates the results of palynostratigraphical investigations of subsurface Tertiary sediments from six bore-holes in the Upper Assam Basin, India. A total of 87 palynofossil genera and 120 species belonging to pteridophytic spores, gymnospermous and angiospermous pollen. Fungal spores and ascostromata and dinoflagellate cysts are recorded. The distributional pattern of palynotaxa demonstrates the reliability of palynofloral assemblages in the demarcation of different litho-units as well as for long distance correlation. The recorded palynofloral assemblages are compared with the previous reported assemblages from the north-eastern region. Qualitative and quantitative analyses of the palynoflora indicate the presence of lowland subtropical rain forest during Palaeogene times. However, in Neogene it shows distinct development of montane vegetation. Palaeoenvironmental condition of deposition of these sediments is also inferred.
A reappraisal of salviniaceous fossils and its implication on the age and depositional environment of Nkporo Shale of Calabar Flank, Nigeria
Authors: Kumaran K.P. Navaneetha , Edet J.J. , Nyong E.E.
Published: September 2022

Integrated floral and faunal (foraminiferal) data permit a precise interpretation of the age and depositional environment of the outcrop section exposed along the Calabar-Itu at 42.5 km point. The outcrop section belongs to the Nkporo Shale of the Calabar Flank from which Ariadnaesporiles nigeriensis Obebode & Skarby was reported and described. The results obtained indicate an Early Maastrichtian age and deposition in a brackish swamp environment. the biostratigraphic and environmental significance of Salviniaceous fossils have been consequently assessed.
Organodebris analysis of Chilka Lake, Orissa, India :an assessment of depositional environment
Authors: Khandelwal Asha , Gupta H.P.
Published: September 2022

This paper presents the result of organic matter analysis from Chilka Lake, Orrisa, India. A co-ordinated attempt has been made to classify and interpret total organic matter (TOM) in relation to the depositional environment. Organo debris analysis dated back to ca 3,200 years B.P. has provided clues that ponding environment gave rise to reducing (anerobic) conditions which probably accelerated microbial activity, transforming the palynodebris into first semi-amorphous/amorphous and then into fine organic matter. Various phases of mangrove vegetation development, the factors responsible for degrading mangals land denudation have also been discussed in the light of multivariate methods of data analysis.
39th Sir Albert Charles Seward Memorial Lecture: Climate changes over space and time: their repercussions on the flora and vegetation
Authors: Meher-Homji V.M.
Published: September 2022

The changes in the climatic types from region to region over the vast expanses of the Indian sub-continent have been examined in terms of quantum of rainfall and distribution of rainy pattern: length of the dry period and season(s) of occurrence of rains. The interyearly variability introduces a further dimension in the diversity of the climate types. The vegetation pattern generated by the climatic diversity is briefly reviewed. Of particular interest is the transition from the tropical type of climate in India to the Mediterranean type further westwards.

As to the climate changes through the geological ages, the impressive record of megafossils collected by the scientists of the Birbal Sahni Institute has yielded valuable evidence of the vicissitudes. For the Quaternary period, palynology has played a key role in reconstructing the climate-vegetational history. A criticism may not be out of place. Many of the reconstructions refer to climate change only in terms of rainfall amount ignoring the distributional pattern (number of dry months, season of occurrence of rains). Sometimes the botanical markers selected are not fidel indicators of climate. In the much acclaimed and frequently cited palaeopalynological study of Gurdip Sing et al., (1974), the taxa selected like Artemisia, Maytenus, Mimosa, Oldenlandia, Cyperus, Syzygium cumini are not very fidel indicators of a humid phase. If the climate of the Thar had changed to humid type in true sense of the term, the pollen of the forest species of the Aravallis should have turned up in the profile of the Sambhar Lake.

In other cases, palynologists in their enthusiasm attribute even man-induced change in the vegetation to climate. The meticulous study of Caratini et al (1991) brings out a distinct change from forest vegetation to savannah type in the Western Ghats 3,500 years B.P., which incidentally pinpoints the beginning of the anthropic activity with burning of vegetation promoting the growth of grass-savanna. In yet other cases, the change in vegetation appears likely due to shifts in the course of river rather than fluctuations in rainfall (Jolly & Bonnefille, 1992).

A hypothesis has been suggested as to how the species responded or adjusted phenologically to the drift over a vast latitudinal span from 30° S to 30° N. it has also been pointed out that major deforestation can bring about a climate change in disrupting the normal rainy pattern decreasing the number of rainy days and drastically altering the micro-climates. The physical mechanisms involved have been enumerated.

Vegetation mapping has provided clues for the areas to be protected on priority basis for conservation of biodiversity and for permitting the migration of species through these protected corridors in the wake of climatic change: from the cooler’s zones to the warmer and from wetter to the drier. The need for study of populations in plant taxonomy has been stresses for assessing finer changes in climate.
Palynostratigraphy of the late cretaceous Nkporo shale outcrop in the Anambra Basin, Nigeria
Authors: Kumaran K.P. Navaneetha , Edet J.J.
Published: September 2022

The palynostratigraphy of the Nkporo Shale outcrop exposed at 84 km point along the Enugu-Umahia Express Way indicates a Late Campanian-Early Maastrichtian age. The spore-pollen/dinocysts ratio in the assemblage is suggestive of a brackish swamp (mangrove) environment of deposition. The relative abundance and dominance of marshy pteridophytes and palm pollen suggest the prevalence of humid tropical climate during the deposition of the Nkporo Shale.
23rd Birbal Sahni Memorial Lecture: Impact of information technology in scientific inquiry
Authors: Viswanathan T.
Published: September 2022

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Revision of the late Permian-Triassic pollen genus playfordiaspora Maheshwari & Banerji 1975
Authors: Vijaya
Published: September 2022

The genus Playfordiaspora was proposed by Maheshwari and Banerji (1975) to accommodate trilete, "apparently monosaccate" miospores with very fine reticulate "flange". The present study reveals that it bears an enveloping single layered, endoreticulate, empty monosaccus without an in-fill. This records the occurrence of eusaccate pollen during Late Permian-Triassic from widely separated palaeogeographical areas of the Gondwanaland, Europe and America. Although, the affinity of Playfordiaspora is difficult to ascertain, a pteridospermous relationship seems probable on the basis of above morphographic features.
Occurrence of dipterocarpus in the mar formation of Bikaner, Rajasthan, western India
Authors: Guleria J.S.
Published: September 2022

The occurrence of fossil wood of Dipterocarpus Gaert n.f. in the sediments of Mar Formation (Plio-Pleistocene) of Bikaner, western desertic part of Rajasthan, is of great significance both climatically and phytogeographically in view of the present day distribution of the genus in India. Its complete absence in the western (Gujarat and Rajasthan) and north-western parts of India today indicates drastic climatic changes in the region since the time of deposition of the fossil.
Occurrence of acrostichum linn., a coastal fern in the Tertiary sediments of Kasauli, Himachal Pradesh, north-west Himalaya
Authors: Awasthi N. , Guleria J.S. , Prasad M. , Srivastava R.
Published: September 2022

A fossil fern frond resembling that of Acrostichum Linn, is described from the Kasauli sediments (Lower Miocene), exposed along Kalka-Shimla road between Kumar Hatti and Barong, Himachal Pradesh. This fern, being primarily coastal in its distribution, is highly significant from the view point of palaeoecology, phytogeography and depositional environment. It indicates near shore tropical conditions and tidal influence in the area during Early Miocene. This is the first megafossil record of Acrostichum from the Tertiary sediments of India.
Distribution, evolution and extinction of global early Carboniferous flora
Authors: Chandra Shaila , Keqin Sun
Published: September 2022

The uniform Lepidodendropsis flora of the Early Carboniferous is uniformly and widely distributed in the Cathaysia, Laurasia, Kazakhstania and Gondwana continents. This is characterized by Lepidodendropsis, Sublepidodendron, Archaeosigillaria, Archaeocalamites, Sphenopteridium, Cardiopteridium, Rhodeopteridium, Rhacopteris, Triphyllopteris and Adiantites, etc. the global climatic differentiation was not very obvious during the Early Carboniferous, therefore, all Early Carboniferous plant assemblages belonged to the same phytogeographic province. It is known that some typical genera of the Lepidodendropsis flora of the Early Carboniferous, such as Lepidodendropsis, Lepidosigillaria and Archaeosigillaria are recorded from the Lower Devonian in Libya, Africa (Lejal-Nicol, 1975) and some elements of this flora are also recorded from the Late Devonian in China and other parts of the world. It is considered that this Lepidodendropsis flora gradually started appearing in the Early Devonian, began to diversify in the Late Devonian and reached its maximum development in the Early Carboniferous. The flora tended to decline in the Late Early Carboniferous and resulted in its extinction in the end of the Early Carboniferous.

Although some plant elements in Cathaysia, Euramerica, Angara and Gondwana had already appeared in the Early Carboniferous, especially in the late Early Carboniferous, the occurrence of the new taxa was regarded as a result of gradually increasing climatic differentiation and plant evolution. During the transition period from the Early Carboniferous to the Late Carboniferous, the differentiations of climatic conditions, tectonic movements, continental positions, oceanic currents and glaciation were quite obvious, resulting in the extinction of numerous typical elements of the Early Carboniferous flora and the appearance of some forerunners of the Late Carboniferous floras in the world. The Cathaysia, Euramerica, Angara and Gondwana floras derived from the identical Lepidodendropsis flora of the Early Carboniferous, but developed and flourished in different environmental conditions.
Silent Valley: A correlation between pollen spectra and vegetation
Authors: Gupta H.P. , Bera S.K.
Published: September 2022

The paper embodies the results of pollen analysis of modern samples in order to work out modern vegetation and pollen relationship. The study has revealed that the pollen/spores assemblage of the modern samples is almost uniform and coheres with the modern vegetation to the tune of 60 per cent. However, the aboreal pollen taxa are either absent or lowly present. The paucity of arboreals is often accounted due to entomophilous mode of pollination in most of the plants. Nevertheless, the predominance of saprophytic fungi present in the samples may have destroyed the pollen/spores.
New species of Gleichenites (Gleicheniaceae, Filicales) from the Upper Triassic of Argentina and Chile
Authors: Herbst Rafael
Published: September 2022

Two new and one undetermined species of Gleichenites are described from the Upper Triassic Canadon Largo Formation (El Tranquilo Group) from Santa Cruz Province, Argentina, The Upper Triassic La Ternera Formation, Copiapo province, northern Chile and the Upper Triassic Gomero-Talcamavida member of the Concepcion area in southern Chile. These funding together with formers one of Argentina, Australia and eventually America, reinforce the idea of a possible austral origin of the family Gleicheniaceae or at least part of it. All the Triassic and part of the Jurassic hitherto known species from the Gondwana realm are multisorate and thus belong to the primitive members of the family included in the sub-genus Diplopterygium in Holttum’s sense.
Geologic significance of land organisms that crossed over the Eastern Tethys "Barrier" during the Permo-Triassic
Authors: Shields Oakley
Published: September 2022

During the Permo-Triassic (P-T), some terrestrial organisms had distributions that spanned the eastern Tethys Sea between Gondwanaland and Asia while avoiding a Northwest African-Southwest European connection. These data strongly suggest that a broad paleotethys ocean-barrier did not exist, while transport across it on displaced terranes leads to further difficulties. Earth expansion overcomes these problems by joining eastern Gondwanaland and southern Asia throughout P-T times. The apparent failure of various plate tectonic models in this region stems from their requirement that the earth's diameter has remained constant through time, thus creating an unnecessarily wide Tethys ocean. Instead, if Paleotethys were a shallow epicontinental seabarrier, it would allow some terrestrial organisms to cross at narrow passage ways during regressions. The data also require India to be connected with Asia in P-T times, whereas plate tectonic models have them separated by a wide ocean barrier then and not rejoined until Eocene times.
Clavadiporopollenites raneriensis gen. et sp. nov. from the Tertiary sediments of Bikaner District, Rajasthan, India
Authors: Ambwani K. , Singh R.S.
Published: September 2022

Clavadiporopollenites raneriensis gen. et. sp. nov. described here is based on the light and scanning electron microscopial observation. The new taxon has been recovered alongwith the typical marker taxa from bore-core no. RGBH-33/14 drilled at Raneri Village in Bikaner District, Rajasthan, India. Clavadiporopollenites is characteristically a diporate pollen with a whorl of clava around each pore and microreticulate exine.
Global extinctions and the biological evolution
Authors: Golubev Vadim M.
Published: September 2022

The biosphere evolution is shown to accompany geodynamic processes and follow different-order cycles of the galactic motion of the Solar System. Restricted to critical points of the cycles are global epochs of nascencies and extinctions of taxa whose rank corresponds to a scale of geodynamic activation at their origin in critical points of the Earth’s surface. Mutations are induced by a cyclic increase in cosmic radiation and provided by synchronous variations of geophysical fields. Rhythmics of physical fields at taxa nascencies is fixed in genotype of organism to form their biorhythms and typical response degree to variations of the fields, reflected in stage-by-stage pattern of their life cycle. Desynchronization of the biorhythms with physical rhythms cause taxa extinctions or re-nascencies that is stimulated by simultaneous catastrophic changes in habitat conditions.
Palynological zonations and paleoecology of Carboniferous sequence from Zhongwei of Ningxia, Northwest China
Authors: Yong-dong Wang
Published: September 2022

Six miospore assemblage zones are established for Carboniferous strata (Namurian-Stephanian) in the Xiaheyan Section of Zhongwei, Ningxia, Northwest China. They correspond to the Early Namurian (goniatite E Zone and H Zone), Late Namurian (goniatite R-G Zone), Westphalian A-B, Westphalian C-D and Stephanian of West Europe, respectively. The general aspect of Carboniferous palynofloral in Zhongwei is dominated by spore types with affinities of Filicopsida and Pteridospermospsida; Sphenopisd and Lycopsid spores occupy the subdominant position, while the gymnospermous pollen grains of Cordaitopsida and Confiferopsida make lesser contribution to the flora. Three miospore phases are recognized in ascending order as Lycospora-Crassispore phase, Laevigatosporites-Torispora phase and Florinites-Pityosporites phase. The palaeoecological considerations of each phase are also discussed.
Continental Triassic biostratigraphy of the Bolshaya Synya and Korotaikha depressions, North CisUrals, Russia: Tetrapod and palynological data
Authors: Novikov Igor V. , Ilyina Nataly V.
Published: September 2022

The study of rich palaeontological samples from the continental Triassic deposits of the Bolshaya Synya and Korotaikha depressions, North CisUrals, Russia, has provided a new evidence of age. Palynological and tetrapod data indicate substantial changes in the dating of the Lower and Middle Triassic units, and allow correlation with the standard stratigraphic scheme established in the East Europe platform and South CisUrals.
Some artificial genera (Fagaceae, Platanaceae, Araliaceae) of Upper Cretaceous of the Northern Hemisphere and heterophylly in some modern hybrids
Authors: Ruffle Ludwig
Published: September 2022

Pedate or three- pieced leaves of Upper Cretaceous angiosperm genera of Europe and North America, Dewalquea, Araliophyllum, Araliopsis and Proteophyllum are investigated for their cuticles. Most of the European samples yielded only one epidermis type pointing to Fagaceae (Castanopsis Pasania), which is confirmed by fine venation. Some specimens of the Czech Cenomanian seem to have belonged to Araliaceae (Oreopanax). In addition, the leaf morphology in question is common in several remains of Platanaceae with comparable cuticles. In view of the phylogeny, Platanaceae and Fagaceae families are closely related. Heterophylly in Lianas and some modern hybrids of Ranunculaceae, Oleaceae and Fagaceae suggests that an apparent irregular leaf-growth predominated during Cretaceous resembling pteridosperms or ferns. In atavistic accelerated meristem grow that the leaf bases and the margins. It is concluded that long or dwarf shoot growth and timbers occurred during Cretaceous. It has been concluded that most of simple leaves of Tertiary and Present time must have been derived from the pedate type of Cretaceous.
Carbonaceous macrofossils and organic-walled microfossils from the Halkal Formation, Bhima Group, Karnataka with remarks on age
Authors: Maithy P.K. , Babu Rupendra
Published: September 2022

Carbonaceous macrofossils., viz., Churia Tawuia, Sinosabeellidites, Protoarenico, Beltina the organic-walled microfossils belonging to Leiosphared, Myxococcoides, Eomycetopsis and vase-shaped forms are recorded from the Halkal Formation, Bhima Group, Karnataka. The overall assemblage supports an older age than the Vendian i.e. 1000-850 Ma.
Climatic significance of growth rings in the Mesozoic woods from India
Authors: Yadav R.R. , Bhattacharyya A.
Published: September 2022

Many of the fossil woods described from the Mesozoic of India possess distinct growth rings which provide valuable proxy data to decipher multitude of environmental information of the concurrent periods. Detailed growth ring study of Podocarpoxylon rajmahalense (Jain) Bose & Maheshwari from Rajmahal Hills, Bihar was conducted to understand the growth environment of the fossil wood. Growth ring features of the fossil wood indicate that it could either be derived from a branch or young stem of a tree growing in the exterior of the forest. Large amount of early wood with only 1-3 rowed latewood cells indicates good soil moisture availability during the growing season. Absence of false rings further adds to the conclusion that the moisture would not have been the limiting factor during the growing season. Warm temperate type of climate would have existed during the life span of the present fossil wood.
Late Cretaceous and Tertiary palynological succession in India
Authors: Kar R.K.
Published: September 2022

The Late Cretaceous and Tertiary palynological assemblages of India are divided into several phytogeoprovinces and cenozones. The Senonian palynofloral of India is clubbed with Brazil and West African palynoflora as Constantinisporis phytogeoprovince characterized by the presence of Constantinisporis, Victorisporis and Andreisporis. The Danian to Middle Eocene palynofloral of India are placed under pantropical Proxapertites operculatus zone and this is further subdivided into Acrostichumsporites meghalayensis subzone, Dandotiaspora dilata subzone, Kielmeyerapollenites syncolporatus subzone, Lakiapollis ovatus subzone, Tricolporopilites robustus subzone and Pellicieroipollis langenheimii subzone. The Oligocene and Miocene palynofossils are placed under Trisyncolpites ramanujamii subzone and Hibisceaepollenites robustispinosus subzone respectively and come under Striatriletes susannae pantropical zone. A comparison of the Indian palynological succession with Borneo, Caribbean and Atlantic Tertiary palynological assemblages reveal that the trans-Atlantic palynological assemblages have closer similarity than others.