Birbal Sahni Institute of Palaeosciences

By sequencing 523 ancient humans, we show that the primary source of ancestry in modern South Asians is a prehistoric genetic gradient between people related to early hunter-gatherers of Iran and Southeast Asia. After the Indus Valley Civilization's decline, its people mixed with individuals in the southeast to form one of the two main ancestral populations of South Asia, whose direct descendants live in southern India. Simultaneously, they mixed with descendants of Steppe pastoralists who, starting around 4000 years ago, spread via Central Asia to form the other main ancestral population. The Steppe ancestry in South Asia has the same profile as that in Bronze Age Eastern Europe, tracking a movement of people that affected both regions and that likely spread the distinctive features shared between Indo-Iranian and Balto-Slavic languages.

This paper provides an updated classification of the Kingdom Fungi (including fossil fungi) and fungus-like taxa. Five-hundred and twenty-three (535) notes are provided for newly introduced taxa and for changes that have been made since the previous outline. In the discussion, the latest taxonomic changes in Basidiomycota are provided and the classification of Mycosphaerellales are broadly discussed. Genera listed in Mycosphaerellaceae have been confirmed by DNA sequence analyses, while doubtful genera (DNA sequences being unavailable but traditionally accommodated in Mycosphaerellaceae) are listed in the discussion. Problematic genera in Glomeromycota are also discussed based on phylogenetic results.

Silicified plant tissues (phytoliths) preserved in Late Cretaceous coprolites from India show that at least five taxa from extant grass (Poaceae) subclades were present on the Indian subcontinent during the latest Cretaceous. This taxonomic diversity suggests that crown-group Poaceae had diversified and spread in Gondwana before India became geographically isolated. Other phytoliths extracted from the coprolites (from dicotyledons, conifers, and palms) suggest that the suspected dung producers (titanosaur sauropods) fed indiscriminately on a wide range of plants. These data also make plausible the hypothesis that gondwanatherian mammals with hypsodont cheek teeth were grazers.

Today, farmers in many regions of eastern Asia sow their barley grains in the spring and harvest them in the autumn of the same year (spring barley). However, when it was first domesticated in southwest Asia, barley was grown between the autumn and subsequent spring (winter barley), to complete their life cycles before the summer drought. The question of when the eastern barley shifted from the original winter habit to flexible growing schedules is of significance in terms of understanding its spread. This article investigates when barley cultivation dispersed from southwest Asia to regions of eastern Asia and how the eastern spring barley evolved in this context. We report 70 new radiocarbon measurements obtained directly from barley grains recovered from archaeological sites in eastern Eurasia. Our results indicate that the eastern dispersals of wheat and barley were distinct in both space and time. We infer that barley had been cultivated in a range of markedly contrasting environments by the second millennium BC. In this context, we consider the distribution of known haplotypes of a flowering-time gene in barley, Ppd-H1, and infer that the distributions of those haplotypes may reflect the early dispersal of barley. These patterns of dispersal resonate with the second and first millennia BC textual records documenting sowing and harvesting times for barley in central/eastern China.

The Late Paleogene surface height and paleoenvironment for the core area of the Qinghai-Tibetan Plateau (QTP) remain critically unresolved. Here, we report the discovery of the youngest well-preserved fossil palm leaves from Tibet. They were recovered from the Late Paleogene (Chattian), ca. 25.5 ± 0.5 million years, paleolake sediments within the Lunpola Basin (32.033°N, 89.767°E), central QTP at a present elevation of 4655 m. The anatomy of palms renders them intrinsically susceptible to freezing, imposing upper bounds on their latitudinal and altitudinal distribution. Combined with model-determined paleoterrestrial lapse rates, this shows that a high plateau cannot have existed in the core of Tibet in the Paleogene. Instead, a deep paleovalley, whose floor was <2.3 km above mean sea level bounded by (>4 km) high mountain systems, formed a topographically highly varied landscape. This finding challenges prevailing views on tectonic processes, monsoon dynamics, and the evolution of Asian biodiversity.

For nearly 100 million years, the India subcontinent drifted from Gondwana until its collision with Asia some 50 Ma, during which time the landmass presumably evolved a highly endemic biota. Recent excavations of rich outcrops of 50-52-million-year-old amber with diverse inclusions from the Cambay Shale of Gujarat, western India address this issue. Cambay amber occurs in lignitic and muddy sediments concentrated by near-shore chenier systems; its chemistry and the anatomy of associated fossil wood indicates a definitive source of Dipterocarpaceae. The amber is very partially polymerized and readily dissolves in organic solvents, thus allowing extraction of whole insects whose cuticle retains microscopic fidelity. Fourteen orders and more than 55 families and 100 species of arthropod inclusions have been discovered thus far, which have affinities to taxa from the Eocene of northern Europe, to the Recent of Australasia, and the Miocene to Recent of tropical America. Thus, India just prior to or immediately following contact shows little biological insularity. A significant diversity of eusocial insects are fossilized, including corbiculate bees, rhinotermitid termites, and modern subfamilies of ants (Formicidae), groups that apparently radiated during the contemporaneous Early Eocene Climatic Optimum or just prior to it during the Paleocene-Eocene Thermal Maximum. Cambay amber preserves a uniquely diverse and early biota of a modern-type of broad-leaf tropical forest, revealing 50 Ma of stasis and change in biological communities of the dipterocarp primary forests that dominate southeastern Asia today.

Observational records and reconstructions from tree rings reflect premonsoon (March to May) temperature cooling in the western Himalaya during the latter part of the 20th century. A rapid decrease of minimum temperatures at around three times higher rate, as compared to the rate of increase in maximum temperatures found in local climate records is responsible for the cooling trend in mean premonsoon temperature. The increase of the diurnal temperature range is attributed to large scale deforestation and land degradation in the area and shows the higher influence of local forcing factors on climate in contrast to the general trend found in higher latitudes of the northern Hemisphere.

The lower cloud layer of Venus (47.5-50.5 km) is an exceptional target for exploration due to the favorable conditions for microbial life, including moderate temperatures and pressures (∼60°C and 1 atm), and the presence of micron-sized sulfuric acid aerosols. Nearly a century after the ultraviolet (UV) contrasts of Venus' cloud layer were discovered with Earth-based photographs, the substances and mechanisms responsible for the changes in Venus' contrasts and albedo are still unknown. While current models include sulfur dioxide and iron chloride as the UV absorbers, the temporal and spatial changes in contrasts, and albedo, between 330 and 500 nm, remain to be fully explained. Within this context, we present a discussion regarding the potential for microorganisms to survive in Venus' lower clouds and contribute to the observed bulk spectra. In this article, we provide an overview of relevant Venus observations, compare the spectral and physical properties of Venus' clouds to terrestrial biological materials, review the potential for an iron- and sulfur-centered metabolism in the clouds, discuss conceivable mechanisms of transport from the surface toward a more habitable zone in the clouds, and identify spectral and biological experiments that could measure the habitability of Venus' clouds and terrestrial analogues. Together, our lines of reasoning suggest that particles in Venus' lower clouds contain sufficient mass balance to harbor microorganisms, water, and solutes, and potentially sufficient biomass to be detected by optical methods. As such, the comparisons presented in this article warrant further investigations into the prospect of biosignatures in Venus' clouds.

Research Article| January 01, 2011 Early Eocene warming events and the timing of terrestrial faunal exchange between India and Asia Mark Clementz; Mark Clementz * 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA *E-mail: mclemen1@uwyo.edu. Search for other works by this author on: GSW Google Scholar S. Bajpai; S. Bajpai 2Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Search for other works by this author on: GSW Google Scholar V. Ravikant; V. Ravikant † 3Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India †Current address: Indian Institute of Science Education and Research Kolkata, Mohanpur 741252, West Bengal, India. Search for other works by this author on: GSW Google Scholar J.G.M. Thewissen; J.G.M. Thewissen 4Department of Anatomy and Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown, Ohio 44272, USA Search for other works by this author on: GSW Google Scholar N. Saravanan; N. Saravanan 2Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India Search for other works by this author on: GSW Google Scholar I.B. Singh; I.B. Singh 5Department of Geology, Lucknow University, Lucknow 226007, India Search for other works by this author on: GSW Google Scholar V. Prasad V. Prasad 6Birbal Sahni Institute of Palaeobotany, Lucknow 226007, India Search for other works by this author on: GSW Google Scholar Author and Article Information Mark Clementz * 1Department of Geology and Geophysics, University of Wyoming, Laramie, Wyoming 82071, USA S. Bajpai 2Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India V. Ravikant † 3Institute Instrumentation Centre, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India J.G.M. Thewissen 4Department of Anatomy and Neurobiology, Northeastern Ohio Universities College of Medicine, Rootstown, Ohio 44272, USA N. Saravanan 2Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India I.B. Singh 5Department of Geology, Lucknow University, Lucknow 226007, India V. Prasad 6Birbal Sahni Institute of Palaeobotany, Lucknow 226007, India *E-mail: mclemen1@uwyo.edu. †Current address: Indian Institute of Science Education and Research Kolkata, Mohanpur 741252, West Bengal, India. Publisher: Geological Society of America Received: 18 Jul 2010 Accepted: 28 Jul 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2011 Geological Society of America Geology (2011) 39 (1): 15–18. https://doi.org/10.1130/G31585.1 Article history Received: 18 Jul 2010 Accepted: 28 Jul 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Mark Clementz, S. Bajpai, V. Ravikant, J.G.M. Thewissen, N. Saravanan, I.B. Singh, V. Prasad; Early Eocene warming events and the timing of terrestrial faunal exchange between India and Asia. Geology 2011;; 39 (1): 15–18. doi: https://doi.org/10.1130/G31585.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The timing of initiation of continent-continent collision between Asia and India is controversial, but this major tectonic event is generally thought to have occurred in the Early Eocene, ca. 50 Ma. New and independent data from strontium isotopes, stable carbon isotopes, microfossil biostratigraphy, and mammal fossils from an Early Eocene marginal marine sequence (Cambay Shale) at the Vastan Lignite Mine of western India indicate that terrestrial faunal exchanges, and therefore continental collision, between Asia and the Indian subcontinent took place before 53.7 Ma. This age coincides with the second Eocene Thermal Maximum (ETM2), a short-lived warming episode that followed the Paleocene-Eocene Thermal Maximum (PETM) ca. 55.5 Ma. Our data also document, for the first time, a clear record of the ETM2 in terrestrial organic material from a low-latitude site, which is represented by a 3‰−4‰ carbon isotope excursion (CIE) in lignite and dispersed organic carbon δ13C values. The magnitude of the CIE at this location closely matches that observed in marine cores from the Arctic Ocean, which supports an interpretation that this hyperthermal event, though of lower magnitude, was similar in character to that of the PETM, being a global phenomenon that affected both terrestrial and marine ecosystems. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Abstract Aim Early in their evolution, angiosperms evolved a diversity of leaf form far greater than that of any other group of land plants. Some of this diversity evolved in response to varying climate. Our aim is to test the global relationship between leaf form in woody dicot angiosperms and the climate in which they live. Location We have compiled a data set describing leaf form (using 31 standardized categorical characters) from 378 natural or naturalized vegetation sites from around the world. Our data include sites from all continents except A ntarctica and encompass biomes from tropical to taiga, over a range of elevations from 0.5 m to over 3000 m. Methods We chose the C limate L eaf A nalysis M ultivariate P rogram sampling, scoring and analytical protocols to test the relationships between climate and leaf form, which is based on canonical correspondence analysis. Cluster analysis evaluates the role of historical factors in shaping the patterns, and pairwise Pearson correlations examine the relationships among leaf characters. Results Woody dicot leaf characters form a physiognomic spectrum that reflects local climate conditions. On a global scale, correlations between leaf form and climate are consistent, irrespective of climate regime, vegetation type or biogeographic history. Relationships with temperature variables are maintained even when leaf margin characters, regarded as being particularly well correlated with mean annual temperature, are removed. Main conclusions In natural woody dicot vegetation an integrated spectrum of leaf form has developed across multiple leaf character states and species. This spectrum appears more strongly influenced by prevailing climate than biogeographic history. The covariation of leaf traits across species suggests strong integration of leaf form. New methods of exploring structure in multidimensional physiognomic space enable better application of leaf form to palaeoclimate reconstruction.

Studies on host-pathogen interaction have identified human ACE2 as a host cell receptor responsible for mediating infection by coronavirus (COVID-19). Subsequent studies have shown striking difference of allele frequency among Europeans and Asians for a polymorphism rs2285666, present in <italic>ACE2</italic>. It has been revealed that the alternate allele (TT-plus strand or AA-minus strand) of rs2285666 elevate the expression level of this gene upto 50%, hence may play a significant role in SARS-CoV-2 susceptibility. Therefore, we have first looked the phylogenetic structure of rs2285666 derived haplotypes in worldwide populations and compared the spatial frequency of this particular allele with respect to the COVID-19 infection as well as case-fatality rate in India. For the first time, we ascertained a significant positive correlation for alternate allele (T or A) of rs2285666, with the lower infection as well as case-fatality rate among Indian populations. We trust that this information will be useful to understand the role of <italic>ACE2</italic> in COVID-19 susceptibility.

This study presents a comprehensive review of the published literature on the evidences of a changing climate in the Indian Himalayan Region ( IHR ) and its impacts on the glacio‐hydrology of the region. The IHR serves as an important source of fresh water for the densely populated areas downstream. It is evident from the available studies that temperature is significantly increasing in all parts of the IHR , whereas precipitation is not indicative of any particular spatiotemporal trend. Glacio‐hydrological proxies for changing climate, such as, terminus and areal changes of the glaciers, glacier mass balance, and streamflow in downstream areas, highlight changes more evidently in recent decades. On an average, studies have predicted an increase in temperature and precipitation in the region, along with increase in streamflow of major rivers. Such trends are already apparent in some sub‐basins of the western IHR . The region is particularly vulnerable to changing climate as it is highly dependent on snow and glacier melt run‐off to meet its freshwater demands. We present a systematic review of key papers dealing with changing temperature, precipitation, glaciers, and streamflow in the IHR . We discuss these interdisciplinary themes in relation to each other, in order to establish the present and future impacts of climatic, glaciological, and hydrological changes in the region. WIREs Clim Change 2016, 7:393–410. doi: 10.1002/wcc.393 This article is categorized under: Paleoclimates and Current Trends &gt; Modern Climate Change

The antiquity and decline of the Bronze Age Harappan civilization in the Indus-Ghaggar-Hakra river valleys is an enigma in archaeology. Weakening of the monsoon after ~5 ka BP (and droughts throughout the Asia) is a strong contender for the Harappan collapse, although controversy exists about the synchroneity of climate change and collapse of civilization. One reason for this controversy is lack of a continuous record of cultural levels and palaeomonsoon change in close proximity. We report a high resolution oxygen isotope (δ(18)O) record of animal teeth-bone phosphates from an archaeological trench itself at Bhirrana, NW India, preserving all cultural levels of this civilization. Bhirrana was part of a high concentration of settlements along the dried up mythical Vedic river valley 'Saraswati', an extension of Ghaggar river in the Thar desert. Isotope and archaeological data suggest that the pre-Harappans started inhabiting this area along the mighty Ghaggar-Hakra rivers fed by intensified monsoon from 9 to 7 ka BP. The monsoon monotonically declined after 7 ka yet the settlements continued to survive from early to mature Harappan time. Our study suggests that other cause like change in subsistence strategy by shifting crop patterns rather than climate change was responsible for Harappan collapse.

Most of the palynozonation schemes so far proposed for the Gondwana sequence of India are based on quantitative representation of spore-pollen genera. These proposals have limited value for interbasinal correlation. The present synthesis deals with a model for species-based stratigraphy. Palynologically well studied Permian and Triassic sequences in the Damodar Graben and Permian, Triassic and Cretaceous sequences in the adjacent Rajmahal Basin have been taken as key regions to establish the zonation scheme. Based on the FADs and LADs and totality of composition of selected species, twenty Species Assemblage-Zones have been recognised. The reorganisation of this data through computer has also resulted in the identification of thirty Species Acme-Zones.

Abstract We provide the first continuous Indian Summer Monsoon (ISM) climate record for the higher Himalayas (Kedarnath, India) by analyzing a 14 C-dated peat sequence covering the last ~8000 years, with ~50 years temporal resolution. The ISM variability inferred using various proxies reveal striking similarity with the Greenland ice core (GISP2) temperature record and rapid denitrification changes recorded in the sediments off Peru. The Kedarnath record provides compelling evidence for a reorganization of the global climate system taking place at ~5.5 ka BP possibly after sea level stabilization and the advent of inter-annual climate variability governed by the modern ENSO phenomenon. The ISM record also captures warm-wet and cold-dry conditions during the Medieval Climate Anomaly and Little Ice Age, respectively.

43 miospore genera have been referred to in this treatise, out of which 15 genera are new to science. These have been diagnosed, described and compared with morphographically comparable other spore genera. The following genera are new - Eupunctisporites gen. nov., Micrpbaculispora gen. nov., Microfovealatispora gen. nov., Indospora gen. nov., Gondisporites gen. nov., Densipollenites gen. nov., Striomonosaccites gen. nov., Distriomonosaccites gen. nov., Verticipollenites gen. nov., Lahirites gen. nov., Hindipollenites gen. nov., Faunipollenites gen. nov., Striapollenites gen. nov., Distriatites gen. nov., and Tumoripollenites gen. nov. Besides these Striatites, Lunatisporites, Striatopodocarpites and Sulcatisporites have been emended. Some supra-generic taxa have also been created such as Siriasacciti, and Rectistriati. From this study some new morphographic features have come to light, e.g. the presence of +- triradiate muri on distal face of a triangular trilete spore; sculptured and zonate saccus-like body in a trilete spore, the occurrence of striated central budies in monosaccate forms: the proximal surface of central bodies in disaccate grains bearing horizontal striations also crossed with vertical, connecting striations in many forms; occurrence of only vertical striations on the proximal side of central body in some saccate grains; occurrence of striations on the proximal as well as distal faces of the central body (1) in the same direction or (2) at right angles to one another in saccate grains. It has also been discovered that the proximal exine of central body in saccate grains may be smooth or microverrucose with indistinct, intrapunetate or intramicroreticulate structure. Bisaceate grains comparable to some modern members of Podocarpaceae are richly represented and non-saccate pollen grain morphographically similar to those of some living species of Ephedra and Welwitschia are also present in the horizon.

Summary Geologically India is divisible into three units (1) Peninsular, (2) Extra‐Peninsular and (3) Jndo‐Gangetic Plain. The Tertiary floras of India can conveniently be divided into two groups — Palaeogene and Neogene. As known today, Palaeogene floras are found only in the Peninsular India, while Neogene occur in both the Peninsular and extra‐Peninsular regions. They are predominantly tropical floras, made up of genera now largely confined to the Old World. A notable feature of the Indian Palaeogene is the occurrence of a few southern hemisphere taxa which may recall the pre‐Cenozoic relationships between India and the Gondwana continents to the south. The London Clay flora shows noticeable general resemblance with the Indian Palaeogene. This feature is discussed taking into account the Tertiary plant fossils known from northern Africa. Phytogeographic comparison is also made with the Malaysian region. It is envisaged that there were large scale migrations and intermingling of floras over Malaysia, India, Arabia and Eastern Africa during Neogene time. Records of Dipterocarpaceae provide significant evidence. Water seems to have been a major factor in controlling the distribution of plants at low latitudes throughout the Cenozoic era. The palaeogeography of India during the Early Eocene and Miocene epochs has been reconstructed on the joint evidence of plant and animal fossils. Much work remains to be done before we shall have a clear understanding of the sources and migrations of the plants which have survived in southern Asia throughout Tertiary times to the present.

A new Holocene curve is generated for the western Indian continental margin. While constructing this curve careful selection of the dates were made by giving due considerations to the genetic characteristics of the dated material. This new curve shows a low at 100 m depth around 14,500 years BP and a rise to 80.m depth around 12,000 years BP showing a rate of ˜10m/1000 years which was followed by astillstand for about 2,000 years. From 10,000 to 7,000 years it rose at a very high rate (˜20 m/1000 years). Beyond 7,000 years BP it showed minor fluctuations.

Fungi are an essential component of any ecosystem and have diverse ecological roles, ranging from endophytes to epiphytes and pathogens to saprobes. The current estimate of fungal endophytes is around 1 million species, however, we estimate that there is likely over 3 million species and only about 150,000 fungal species have been named and classified to date. Endophytes inhabit internal plant tissues without causing apparent harm to the hosts. Endophytes occur in almost every plant from the coldest climates to the tropics. They are thought to provide several benefits to host plants and improve the hosts’ ability to tolerate several abiotic and biotic stresses. Endophytes produce secondary metabolites with biotechnological, industrial and pharmaceutical application. Some endophytes appear to be host-specific, while some are associated with a wide range of hosts. We discuss the importance of endophytes. The ability to switch lifestyles from endophytes to pathogens or saprobes is discussed. Interactions between endophytes and hosts based on fossil data is also highlighted. Factors that influence the specificity in endophytes are discussed. We argue that the endophytic lifestyle is a common strategy in most fungi and that all fungi have endophytic ancestors. We critically evaluate the influence of co-evolution based on fossil data. We hypothesise the influence of specificity on the estimated number of endophytes and overall species numbers, and present examples of metabolites that they produce. We argue that studying endophytes for novel compounds has limitations as the genera recovered are limited. However, if saprobes were chosen instead, this would result in a much higher species diversity and undoubtedly chemical diversity.

To date, there is a gap in the data about the state and mass balance of glaciers in the climate-sensitive subtropical regions during the Little Ice Age (LIA). Here, based on an unprecedented tree-ring sampling coverage, we present the longest reconstructed mass balance record for the Western Himalayan glaciers, dating to 1615. Our results confirm that the later phase of LIA was substantially briefer and weaker in the Himalaya than in the Arctic and subarctic regions. Furthermore, analysis of the time-series of the mass-balance against other time-series shows clear evidence of the existence of (i) a significant glacial decay and a significantly weaker magnitude of glaciation during the latter half of the LIA; (ii) a weak regional mass balance dependence on either the El Niño-Southern Oscillation (ENSO) or the Total Solar Irradiance (TSI) taken in isolation, but a considerable combined influence of both of them during the LIA; and (iii) in addition to anthropogenic climate change, the strong effect from the increased yearly concurrence of extremely high TSI with El Niño over the past five decades, resulting in severe glacial mass loss. The generated mass balance time-series can serve as a source of reliable reconstructed data to the scientific community.