bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Palaeogene vegetation of peninsular India (Megafossil evidences)
Authors: Bande M.B. 
Published: September 2022

The Palaeogene represents the age of spread and diversification of angiosperms in the Indian sub-continent. A comprehensive knowledge of the Palaeogene flora of peninsular India is, therefore, necessary to decipher the history of the modern flora of India. The Palaeogene plant megafossils of this region can broadly be considered under (i) Deccan Intertrappean flora, (ii) Eocene flora of Kutch, (iii) Eocene plant fossils described from the Fuller's earth deposits near Barmer in Rajasthan, and (iv) Eocene plant records from Meghalaya.
The flora as a whole is characteristically tropical in character. It consists of taxa belonging to marine, estuarine, freshwater, and terrestrial habitat with both evergreen and deciduous forms. It is suggestive of an equable warm and moist tropical climate over the whole of peninsular India during the Palaeogene. The existence of this type of climate was the result of (i) a more or less equatorial position of peninsular India during the Palaeocene-Eocene period, and (ii) a warm sea which not only surrounded the peninsula from all the sides but also intruded into the landmass.
Most of the plants recovered from the Palaeogene localities of peninsular India still continue to grow in various forests of this region. Part of this flora, thus, can be considered to be the ancestral stock for the present-day flora of India. Occurrence of some African, Madagascarian, Australian and South American elements in this flora suggests India's past connections with these Gondwanaland countries.
Holocene history of mangrove vegetation in India: a palynological interpretation
Authors: Khandelwal Asha 
Published: September 2022

Mangroves are defined as the tropical intertidal plant community which thrives both on the eastern and western coasts in India. Considerable work has been carried out on the floristics and economic potential of mangrove vegetation. It has been recently realised that the major part of coastland is transformed into the bareland, though no definite single reason can be assigned for the extermination of mangroves from the Indian coasts.
In view of problems, related to the causes of degradation and extermination of mangroves, the awareness amongst palaeobiogeographers and palynologists is well exemplified by undertaking palynological investigations of estuarine sediments. It has been observed that the eastern and western coasts of India are not comparable; rather they differ greatly in the vegetational composition. The investigated areas are: Gangetie-Sunderbans, Mahanadi- Brahmani, Godavari and Cauvery deltas on the eastern coast and back water sediments from Kutch, Maharashtra, Gujarat, Kerala and Karnaraka on the western coast. A synthesis and interpretation of available palynological data, has been given in order to reconstruct the palaeofloristics and translate them in terms of various events and episodes which had occurred during the Holocene Epoch. The causes of mangrove deterioration in time and space and coordinated scheme for greening the coastland have also been discussed.
Bryophytic remains from the early Permian sediments of India
Authors: Chandra Shaila 
Published: September 2022

Bryophytic fossil remains in the Permian Gondwana formations are extremely rare. The rarity of fossil bryophytes is generally attributed to their delicate nature and small size of the plants. Fossil bryophytes so far reported are few as compared to vascular plants but they have been adequately recorded to indicate early existence of mosses and liverworts. It is also likely that bryophytes have just not been recognized in ancient sediments by palaeobotanists and they may not be so rare as are believed today. Most of the fossil specimens reported from India as bryophytes are either doubtful records or unidentifiable up to generic level, Indian Permian reports are considered doubtful while Triassic and younger records are not so meagre and are reasonably well reported.
It is for the first lime a good assemblage of bryophytes has been recovered from the Early Permian sediments of India as impressions along with the typical Glossopteris flora. Both the groups Hepaticae and Musci are represented by newly designated form genera and species. The assemblage is represented by an indeterminate genus - Bryothallites talchirensis, hepatic genus- Hepaticites umariaensis, and three moss genera- Talchirophyllites indicus, Saksenaphyllites saksenae and Umariaphyllites acutus. Remarks on the naming of the fossil bryophytes, their probable possibility of preservation, spore distribution, probable habitat and evolutionary aspects also have been given and discussed.
Tertiary evolution of Caribbean vegetation in the context of geologic and nearshore marine events
Authors: Graham Alan 
Published: September 2022

Estimates of SST (sea surface temperature) during the Cenozoic are complicated by uncertainty as to the presence, extent, and effect of glaciers in the Paleogene, and by an emerging re-evaluation of the accuracy of foraminifera to precisely record changes in equatorial ocean water temperatures in the Neogene, especially at the last glacial maximum (18,000 years B.P.). If Paleogene marine temperatures were as warm as at present, Early Tertiary floras deposited at the ocean-continent interface should record vegetation comparable in ecological import to that of the present. The middle (?) to Late Eocene Gatuncillo flora from Panama (9° N latitude) is similar to the modern vegetation along the north (Atlantic) coast of southern Central America. This argues for the presence of limited glaciers, probably on Antarctica, to account for the increasing 18O in the marine waters. Assuming that any cooling of low latitude SST’s in the late-glacial extended into early glacial times, at least to some extent, Neogene floras should reflect these cooler conditions. The Middle Pliocene (N20; 4-5 Ma) Paraje Solo palynoflora from coastal southeastern Mexico (~18° N latitude) suggests a MAT (mean annual temperature) at least 2°-3°C cooler than at present. The cause(s) likely involved continued decline in CO2 concentration, threshold changes in ocean water circulation, upwelling, deposition just prior to closure of the Isthmus of Panama (~3.5-2.5 Ma) which strengthened poleward transport of ocean heat, and also orbitally induced global lowering of temperatures. The temperature change suggested by the Middle Pliocene Paraje Solo palynofloral is about mid-way between the calculated ~5° C cooling by 18,000 yrs B.P., based on the 18O/16O ratios and strontium evidence from Barbados corals, and the CLIMAP (Climate Long-range Investigation and Mapping Program) estimated of stable equatorial SST about as warm as at present.
Aspect and appraisal of Late Quaternary vegetation of Lower Bengal Basin
Authors: Chandra Sunirmal , Hait Arghya K. 
Published: September 2022

Available information, including the latest ones, on palynological investigations of Late Quaternary deposits of Lower Bengal Basin revealed the existence of brackish water swamp forest similar to the present day mangrove forest of Sundarbans in four different periods, viz., ca. 32,000 ca. 22,000, ca. 14,500 and ca. 7000 yrs B.P, established by radiocarbon dating. Consideration of present day environment of mangroves of the Sundarbans reflects their intertidal habitat. Sea-level changes in the Lower Bengal Basin demonstrates recurrent mangrove forest through the Late Quaternary using pollen analytical method and study of logs of woods in semi-decomposed state. Attempts have been made here to collocate the fossil data with Carbon 14 dating.
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A palynological study on Upper Palaeozoic sediments in the palaeosuture zone area (W. Yunnan, China) and its phytogeographical significance
Authors: Weiping Yang 
Published: September 2022

Several important findings of Late Palaeozoic palynomorphs in the different blocks of West Yunnan have been made in the present palynological investigation. The Granulatisporites frustulentus assemblage (Playford, 1976), typically distributed in Gondwana subcontinent, has been found in Sipaishan, Gengma. It could be roughly divided into the Grandispora spiculifera assemblage (Tournaisian) and the Anapiculatisporites largus - Lycospora pusilla (Visean) assemblage respectively, which have been correlated with those in West Europe and Australia. An attempt has been made to correlate these Gengma assemblages to the standard West Europe miospore zones of BP, PC(?) and Pu. Some Early Permian miospores have been recovered in Haibang, Ali and Kongshuhe, Tengchong respectively. The miospores found in Haibang are characterized by some Carboniferous relict genera, such as Lycospora, Densosporites, but dominated by Protohaploxypinus, Striatopodocarpites, which are the typical representatives in Gondwana palynological province. Jayantisporites pseudozonatus and Microhaculispora tentula, typically distributed in the Lower Permian of the Collie Basin, Western Australia, and Karoo Basin in South Africa, have been found in Kongshuhe, Tengchong. Therefore, it is obvious that the Gondwana microflora had once arrived in Tengchong and even in the Changning-Menglian belt in West Yunnan during Early Carboniferous and Early Permian. In Simao block, North Hemisphere palynomorphs were dominated in Late Carboniferous Namurian section and Late Permian Dengkong section without the mixture of Gondwana-type palynomorphs.
The miospore similarities of western Yunnan with both West Europe and Australia in Early Carboniferous and with Australia solely in Early Permian indicate that West Yunnan was perhaps located much further to the west (Early Carboniferous) and south than the previous continent reconstruction. Such a miospore conclusion seems to coincide with the palaeomagnetic data analysis.
Evolutionary stages of Triassic flora in Siberia (Angarida)
Authors: Mogutcheva N.K. 
Published: September 2022

The Triassic flora of Siberia has been studied from three series of Triassic system in continuous sections. Therefore, its successive alterations and stages in the evolution throughout Triassic from the P/T boundary may be traced. Due to alternation of floristic complexes and marine deposits, the age of floristic complex may be precisely determined. The most ancient complex is studied from Induan deposits. In a single section Permian cordaitean flora is replaced.
In Siberia, the Early Triassic flora is heterogeneous. Two major floras, occupying different ecological niches, are distinguished: the lycopod flora (dominated by Tomiostrobus and Pleuromeia) being confined to marine plain, and the conifer fern (Korvunchanskaya) flora is distributed within intracontinental areas where intense volcanism had occurred at that time. The Middle Triassic flora is scanty in Siberia. The Early Ladinian flora differs from both the Early Triassic and Late Triassic ones, while the Late Ladinian flora is closely related to the Late Triassic flora.
Plant tissue culture and biotechnology
Authors: B.M. Johri  , P.S. Srivastava  , Madhumati Purohit  
Published: September 2022

Plant tissue culture has progressed steadily ever since its inception in 1902. The initial experiments related to various tissues that could sustain prolonged in vitro conditions. The differential response of the cultured tissues under variable chemical milieu provided the necessary impetus to utilize the technique in a profitable manner. Over the years efficacy of the technique became apparent when noticeable in vitro morphogenic responses could be used to unravel the mysteries of growth and differentiation. Expectedly, therefore, any morphogenic event expressed in vitro could be correlated to the specific components of the nutritive medium.
By the 1970s the applicability of the technique came to be realized with the possibility of exploring somatic hybridization, micropropagation of recalcitrant species, haploid, and triploid plants, and finally genetic manipulations. Today, plant tissue culture has become an integral part of biotechnology and is being routinely employed for the improvement of crops and legumes- the backbone of human nutrition that can also aid in the amelioration of malnutrition of millions of sufferers. The ultimate success with the transfer of 'nif’-gene to non-leguminous plants would help save millions of dollars in chemical fertilizers which can then be profitably used for the welfare of the human race.
Dominant gymnosperms of the Glossopteris flora
Authors: Pant D.D. 
Published: September 2022

The paper presents, new ideas about the Lower Gondwana forests which the author believes were dominated by deciduous gymnospermous trees of Glossopteris and its allied genera. It is suggested that the larger trees of glossopterids may have been 30 to 40 m or more in height and below them grew shorter trees and shrubs of Glossopteris and its allies. The large size of glossopterid trees is suggested by that of tree trunks assigned to Dadoxylon sp. from the Raniganj Stage where Glossopteris is the commonest fossil and the genus Noeggerathiopsis, to which they had been assigned earlier, is a rarity. Such trees could have been supported by horizontally spreading axes or roots at the base of the trunks as suggested by fossil axes or roots around missing trunks reported from the bed of Vaal River in South Africa which too had been assigned to Noeggerathiopsis.
The deciduous glossopterid trees are compared with those of modern Ginkgo biloba. It is suggested that the gradate series of glossopterid leaves with Glossopteris having a midrib and anastomosing laterals at one end of the series followed by leaves of Gangamopteris with anastomosing laterals and no midrib. Rhabdotaenia with a midrib and dichotomising non-anastomosing laterals. Palaeovittaria with a midrib in the lower half and non-anastomosing spreading laterals, in the distal part. Rubidgea without a midrib and spreading arched laterals and Noeggerathiopsis with dichotomising spreading straight veins at the other end may form a series of leaves which may be related to each other. It is considered that Noeggerathiopsis may not be a cordaite.
The morphological nature of the fertiligers of glossopterids are discussed and compared with certain abnormal peduncles of Ginkgo biloba and it is pointed out that 10 per cent of the leaves of this genus show anastomoses and this genus may be allied to Glossopteris. In addition, indubitable evidence in support of the in situ or autochthonous mode of formation of Lower Gondwana coal is also discussed.
Petrography, genesis and deposition of tertiary coals from Northeastern India
Authors: Misra Basant K. 
Published: September 2022

The coalfields of Arunachal Pradesh, Assam and Nagaland are disposed along a linear belt of overthrusts where the coal-bearing Oligocene (Tikak Parbat Formation, Barail Group) strata are folded and dispersed into a number of thrust slices. Whereas, in Garo, Khasi and Jaintia hills of Meghalaya the coal seams are associated with an almost undisturbed and sub-horizontal Late Palaeocene Sylhet/Tura formations of Jaintia Group.
The coals are bright, non-banded, vitrinite-rich and have moderate to low amounts of liptinite and inertinite macerals. Pyrite and calcite are the dominant associated minerals, besides generally low proportions of clay and quartz. The coals have moderate to very high amounts of fluorescing macerals consisting chiefly of perhydrous vitrinite. liptodetrinite and resinite. Macerals, cutinite, sporinite, suberinite, exsudatinite, alginite and fluorinite are also present. The rank of the coals ranges between high volatile bituminous C and B stages, on the basis of vitrinite reflectance (Garo Hills: 0.54-0.62%: Jaintia Hills: 0.68-0.81 % and Assam: 0.70-0.74%).
The coals from northeastern India were derived essentially from tropical deciduous mangrove-mixed angiospermous forest vegetation. The coals, presumably, originated from autochthonous to hypo-autochthonous eutrophic peat accumulations in lagoons and/or near-shore back swamps in Assam. Arunachal Pradesh and Nagaland and in small isolated estuarine back swamps in Meghalaya. The vegetal maller, in general, was subjected mainly to anaerobic biodegradation under neutral to mildly alkaline subaqueous conditions and facilitated the precipitation of early diagenetic pyrite and calcite and in situ release of plant bound minerals in the peal. Seasonal freshwater ponds or lakes developed occasionally on the ancient-peat surfaces hosted the growth of aquatic and water-edge taxa whose remains are present in the coal seams. Especially pteridophytic herbaceous and shrubby vegetation growing in the vicinity of ancient peat swamps appear to be mainly responsible for the presence of structured and detrital inertinites. Occasional burning of the wet peat surfaces has been inferred to be the reason for relatively high inertinite contents in the coals from Meghalaya. It has also been presumed that whenever biodegradation of organic matter was severe the normal supply of vegetal matter fell short to produce a peat layer. instead some minor and major authigenic partings were developed within the pre-existing peal. The variation in the rank and thickness of the coal seams was presumably controlled by the prevailing geothermal gradient and tectonic conditions in different areas.
A tree ring reconstruction of climatic extreme years since 1427 AD for Western Central Asia
Authors: Esper Jan , Treydte Kerstin , Gartner Holger , Neuwirth Burkhard 
Published: September 2022

Analyses of ring width values of 429 trees from twelve Juniperus sites and three mixed sites (Juniperus, Picea, Pinus) of the northwest Karakorum in Pakistan and seven Juniperus sites of the southern Tien Shan in Kirghizia enable the reconstruction of extreme years since AD1427. Extreme growth reactions are classified as (i) event years- reflecting extreme years of individual trees, (ii) site pointer years- reflecting common extreme years within a site, (iii) regional pointer years- reflecting common extreme years within the Karakorum or Tien Shan, and (iv) inter-regional pointer years- reflecting synchronous extreme years between the Karakorum and Tien Shan. A comparison between the Karakorum and Tien Shan results in eight positive inter-regional pointer years (1916, 1804, 1766, 1703, 1577, 1555, 1514, 1431 AD) and 17 negative inter-regional pointer years (1917, 1877, 1871, 1833, 1806, 1802, 1790, 1742, 1669, 1653, 1611, 1605, 1591, 1572, 1495, 1492, 1483 AD). These years are valid for Western Central Asia.
The extreme year reconstructions from the Karakorum and Tien Shan Mountains are dominated by regional pointer years. Regional pointer years result from climatic conditions limiting tree growth independent of site ecology, from the lower, arid, to the upper, humid timberlines, and in different exposures. The seasonal climatic forcing of regional pointer years changes from year-to-year, but temperature variation predominantly limits tree growth. Additional analyses of selected site pointer years, which do not belong to regional pointer years, prove temperature signals from sites near the upper timberline, and precipitation signals from sites near the lower timberlines.
An interpretation of the palynology and palaeoecology of the Early Miocene Dulte Formation, Mizoram, India
Authors: Mandaokar B.D. 
Published: September 2022

A palynological study of the Early Miocene sediments of the Aizawl Basin, Mizoram is presented. The Aizawl Basin is part of the North-East India Dulte Formation (Surma Group: Bhuban Subgroup). The significant elements of the palynoassemblage are: Pteridacidites, Striatriletes, Polypodiisporites and Schizaeoisporites (pteridophytes), Compositoipollenites, Malvacearumpolli, Spinizonocolpites, Bombacacidites, Ctenolophonidites, Polyporina, Polyadopollenites, Graminidites (angiosperms), Cucurbitariaceites, Dicellaesporites and Phragmothyrites (fungi).
The shale contains abundant plant remains and white gastropod shells. The alternation of shale-siltstone, sandstone-claystone and the palynoflora suggest an Early Miocene age for studied sequence. Palaeoecological interpretation based upon recent botanical affinities of the fossil spores and pollen highlights the presence of mangrove, fresh water, swamp and water edge ecological groups. The presence of fungal remains indicates warm and humid climate. The composition of palynological assemblage suggests that Dulte Formation was deposited in deltaic conditions rich in terrigeneous detritus where the fungal elements thrived.
Palynological investigation and environmental interpretation on Akli Formation (Late Palaeocene) from Barmer Basin, western Rajasthan, India
Authors: Tripathi S.K.M. , Singh U.K. , Sisodia M.S. 
Published: September 2022

Akli Formation of Barmer Basin, mainly a claystone, shale and lignite sequence, is divided into two members viz.., Thumbli Member and Kapurdi Fuller's earth Member. Palynological studies on samples from the Thumbli Member exposed near Barmer, western Rajasthan were carried out and a rich palynological assemblage constituted by dinoflagellate cysts, fungal remains, pteridophytic spores and angiospermic pollen was recorded from shale and lignite samples. The assemblage is dominated by angiospermic pollen which are assigned to the families Arecaceae, Liliaceae, Oleaceae, Caesalpiniaceae, Rubiaceae, Meliaceae, Myricaceae, Onagraceae and Lamiaceae. Palynotaxa having affinity with Arecaceae are abundant indicating deposition of sediments in coastal environment. Many pteridophytic spores and abundant fungal remains in the assemblage indicate warm and humid climate with high precipitation. Presence of dinoflagellate cysts indicates marine influence.
Most of the families represented in the assemblage are presently confined to tropical to subtropical areas. Considering the high frequency of Nypa/Nypa-like pollen in the assemblage it is inferred that sediments were deposited in an area which was fringed by thick vegetation of mangrove chiefly constituted by Nypa.
Holocene history of vegetation and climate of fresh-water Punlota (Degana) Lake in Eastern Rajasthan, India
Authors: Sharma Chhaya , Srivastava Chanchala , Yadav D.N. 
Published: September 2022

Pollen analysis of 2 m deep sedimentary profile from fresh-water Punlota Lake situated at the outskirt of Degana township in district Nagaur (Eastern Rajasthan), has revealed that around 9,000 years BP, the region had predominantly non-arboreal vegetation, depicting arid climatic conditions. Around 4,200 years BP, savannah type-vegetation covered the region demonstrating increase in the frequency of fem as well as fungal spores- indicating warm and moist conditions. Around 3,000 years BP, savannah vegetation witnessed reduction in tree taxa, ferns and grasses with simultaneous increase in Cyperaceae, Chenopodiaceae, etc.: depicting decrease in the warm and moist conditions. Uppermost part of the investigated profile has revealed more or less similar conditions as witnessed in the preceding phase, except for the increase in Poaceae and Caryophyllaceae, reflecting comparatively drier climate.
Simultaneous elemental analysis of the profile reveals that all major (Al, Fe, Ca and Mg) and trace (Mn, Ba, Sr, Pb, Cu, Ni and Zn) elements change in their concentration at the middle of the profile or about 1 m depth from the surface i.e., around 4,200 years BP. Most of these elements abruptly increase by a factor of two or three at this section and maintain relatively higher values up to the surface. Higher elemental abundance above 1 m boundary in the sediment could arise due to accelerated weathering as well as in consequence to the enhancement in the rainfall.
Coupling radiometric data with major change in elemental abundance indicate maximum precipitation around 4,200 years BP, in the region which very well corroborate with the present palynological studies- the first radiocarbon dated Holocene profile from the fresh-water lake in Rajasthan.