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1.
Summary A study of fossils in thin sections of a sample from the uppermost Krol E Member in the Mussoorie Hills of the Lesser Himalaya, India, proves the existence of morphologically differentiated calcified sponges within the Precambrian-Cambrian boundary time interval. The sponges, described as Mussooriella kroli n.g., n.sp. and Maldeotaina composita n.g., n.sp. indicate the presence of different organization grades at the Precambrian-Cambrian interval. Mussooriella had a calcareous skeleton consisting of skeletal elements composed of an inner laminated part and a distinct peripheral layer with knobs. Maldeotaina is characterized by a stromatoporoid-grade growth pattern following a thalamid-grade pattern. The stromatoporoidgrade part of the skeletons reminds strongly on skeletal elements common in labechiid Ordovician and younger stromatoporoids. Maldeotaina also shows criteria of Early Cambrian fossils, originally described as stromatoporoids and later excluded from this group and transferred to archaeocyaths. These similarities point to an Early Cambrian age of the fossil-bearing horizon in the topmost Krol E Member. Growth cavities with crypts indicate that the sponges might have contributed to the formation of small metazoan reefs-like structures. Although the study is based on limited material and many interpretations are still tentative, a thorough documentation of the preliminary results seems reliable considering the high potential of the fossils of the upper Krol Formation important source in understanding of early metazoan differentiation.  相似文献   

2.
Though trace fossils have been recorded from the Tal Group of the Krol-Tal Belt by earlier workers, most of the records are at generic level only. This paper describes, in detail, 24 ichnospecies from 20 ichnogenera, some of which are being reported for the first time, from the Ganog and Koti Dhaman sections of the Nigalidhar Syncline, H.P. Based on the ichnostratigraphic and ichnofabric analyses these ichnofossils have been categorized into three ichnoassemblages, namely Palaeophycus-Phycodes, Daedalus-Phycodes, and Cruziana Ichnoassemblages. An attempt has also been made for correlation of the Tal sections with other Precambrian-Cambrian sections of the world.  相似文献   

3.
Knowledge of the Early Cretaceous ammonoids of the NW‐Himalayas was poor until recent discoveries. Intense sampling from the Giumal Formation exposed near the village of Chikkim (Spiti Valley, Himachal Pradesh, India) led to the recognition of a new Early Cretaceous ammonoid fauna. The succession consists of arenitic sandstone interbedded with shale that was deposited by turbidity currents on an unstable shelf in the Early Cretaceous. Ammonoids have been obtained only from sandstone beds in the lower one‐third and close to the top of the c. 350‐m‐thick section. Eight new ammonoid taxa (1 genus and 7 species) are described: Sinzovia franki sp. nov. (rare), Giumaliceras giumaliense gen. et sp. nov. (abundant), Giumaliceras bhargavai gen. et sp. nov. (rare), Neocomites (Eristavites) platycostatiformis sp. nov. (rare), Cleoniceras oberhauseri sp. nov. (abundant), Australiceras himalayense sp. nov. (rare) and Deshayesites fuchsi sp. nov. (rare). Sinzovia and Deshayesites are reported for the first time from the Tethyan Himalaya. According to the biostratigraphic relevance of some ammonoid taxa described here, the age of the Giumal Formation can be constrained from Berriasian (Giumaliceras assemblage) to Aptian (Cleoniceras assemblage). The discovery of the new fauna substantiates the significance of the Giumal Formation around Chikkim and facilitates comparison with faunal assemblages from other regions in the Tethys Ocean and beyond.  相似文献   

4.
《Palaeoworld》2014,23(3-4):209-224
Large acanthomorphic acritarchs have been previously reported from the Ediacaran successions of the Pachmunda and Krol Hill synclines in the Outer Krol Belt of Lesser Himalaya, India. Thin sections of chert from Krol ‘A’ Formation in Khanog and Rajgarh synclines, Outer Krol Belt, record an equally well developed and diversified assemblage of Ediacaran large acanthomorphic acritarchs. This assemblage contains specimens belonging to seven genera and ten species, identified as: Appendisphaera fragilis, A. grandis, Asterocapsoides sp. A, Asterocapsoides sp. B, Cavaspina acuminata, C. basiconica, Eotylotopalla dactylos, Knollisphaeridium sp., Papillomembrana sp., and Weissiella cf. grandistella. It also contains five unnamed forms, viz. A, B, C, D, and E. The Krol acritarch assemblage shows a close resemblance with the Upper Doushantuo or Tanarium anozosTanarium conoideum assemblage of China. However, the absence of biostratigraphically important markers such as Tanarium anozos and T. conoideum from the Krol assemblage, so far, makes it difficult to establish a definite biostratigraphic correlation between the two assemblages. The current observations from this new locality provide additional data for regional and global biostratigraphic correlation, and significantly increase the purview of Ediacaran sequences for global biostratigraphic zonation.  相似文献   

5.
《Palaeoworld》2020,29(4):729-743
Clastic rich Hangu Formation of the Early Paleocene exposed at the apex of Hazara-Kashmir syntaxis, is significant in providing evidence of the regional Mesozoic–Cenozoic unconformity and nature of detritus supplied. The current study focuses on U-Pb age dating of the detrital zircons along with spinel geochemistry to interpret tectonic implications on provenance. The Hangu Formation is composed of coarse grained sandstone, arenaceous limestone, carbonaceous shale and laterite around the Paras region and rests unconformably over Mesozoic Samana Suk Formation. The probability density plots of the detrital zircons of the Hangu Formation exhibit strong similarity to the Tethyan Himalayan detrital record. The younger Mesozoic detrital zircons exhibit resemblance to Tethyan Himalayan as well as ophiolitic detrital suites, but are very few compared to their coeval Stumpata, Jidula and Denggeng/Sangdanlin formations. The quantitative comparison reflects strong resemblance to the Tethyan Himalaya, whereas, the ophiolitic component relationship is quite poor. Comparison of spinel geochemical data with Northwestern ophiolites (Chilas Ophiolites) and Tethyan Himalaya exhibits mixed source regime of the Hangu sediments. However, the combined U-Pb dating, sandstone petrography and spinel geochemical data suggest that the detritus of the Hangu Formation is mainly derived from the Tethyan Himalayan source (Indian source). The absence of ophiolitic signature in petrography and U-Pb geochronology may suggest that the northern ophiolites were not exposed to provide detritus to the Early Paleocene Hangu Formation. This may also be interpreted that the ophiolites were emplaced during the Late Cretaceous on the northern Indian margin but uplifted and eroded later with the final India–Eurasia collision, which is clearly recorded in various studies all along the Indian margin. This fact also intimates the ophiolite emplacement as a possible cause of the regional Mesozoic–Cenozoic unconformity.  相似文献   

6.
Stellaria devendrae sp. nov. (Caryophyllaceae) is here described and illustrated from the Uttarakhand state of the Indian western Himalaya. It differs from the allied S. monosperma Buch.‐Ham. ex D. Don and S. paniculata Edgew. in having sub‐sessile, oblanceolate or obovate leaves with non amplexicaul, rounded to sub‐auricled leaf base; an inflorescence of a terminal, regularly and simply branched panicle of cymes; larger flowers (5–8 mm across); 5‐lobed floral disc; relatively larger sepals (4–7 mm long); petal lamina lobed for more than 1/2 to 4/5 of the lamina; filaments opposite sepals with prominent nectar glands at base; adjoining filaments not fused at base, and an inconspicuously reticulate‐papillate seed surface.  相似文献   

7.
A new species of the genus Ranunculus, R. uttaranchalensis, is described from Gangotri National Park, Uttaranchal in Western Himalaya, India. It is distinguished from the closely allied R. lobatus in having radical leaves sub‐cordate with hairy lamina base and petiole hairy above; cauline leaves sessile, 3–7 lobed with linear to narrowly lanceolate lobes; sepals usually reddish brown, externally hairy; petals rounded‐obovate and oblong, receptacle glabrous except 1–3 hairs at the top.  相似文献   

8.
A complete post-incisor upper dentition and a left mandible with P/3-M/3 of the proviverrine hyaenodontid (Creodonta: Mammalia)Paratritemnodon indicus, which was hitherto known by heavily worn P/3-M/3, are described from the uppermost Subathu Formation (Middle Eocene) of the Kalakot-Metka-Mohgala area, Rajauri District, Jammu and Kashmir.P. indicus is most closely related to the North American Early Eocene proviverrine,Tritemnodon; its relationships withProdissopsalis from the Middle Eocene of Europe andPropterodon from the Middle to Late Eocene of China are also close. In the Kalakot Eocene vertebrate community of the Subathu vertebrate bioprovince,P. indicus is the only land dwelling carnivorous mammal against more than 20 species of herbivorous mammals, a majority of which are larger than it. This is viewed as an imbalance in trie community and it reflects an immaturity of the ecosystem supporting the fauna. The scarcity of carnivore remains in the Kalakot mammalian fauna is not an artifact.  相似文献   

9.
《Palaeoworld》2021,30(4):610-626
An assemblage of microfossils of moderate diversity, with the remarkable occurrence of ECAP acritarchs, is reported from the Ediacaran Krol ‘A’ (= the Mahi Formation) succession of Lesser Himalaya, India. Microfossils occur in the chert nodules exposed in Solan district, Himachal Pradesh. Two microfossils, Barogophycus symmetricus n. gen. n. sp. and Botominella lineata are new to the well-established Krol assemblage. The paper concentrates predominantly on fossil eukaryotic filamentous and coccoidal micro-organism of simple morphology. The assemblage is dominated by remains of prokaryotic cyanobacteria and demonstrates the diversity achieved by microorganisms at the beginning of the Ediacaran Period in the aftermath of the Marinoan glaciation. Filamentous and coccoidal microorganisms differ in taxonomic composition from the Mesoproterozoic microbiotas. The Krol microfossils assemblage has biostratigraphic potential and usefulness in broadly demarcating the different levels of the Ediacaran strata. Because of the presence of ECAP acritarchs, along with the appearance of other eukaryotic microorganisms of filamentous and coccoidal morphology, the general level of the Krol ‘A’ assemblage is considered as Ediacaran.  相似文献   

10.
Abstract

Integrated ichnology, sedimentology and sequence stratigraphy of the Lower Quartzite Member to the Arkosic Sandstone Member of the Koti Dhaman Formation (Cambrian Series 2, Stage 4), Tal Group, Nigali Dhar Syncline, Lesser Himalayan lithotectonic zone are presented. Trilobite traces of Gondwanan affinity i.e., Cruziana salomonis, Cruziana fasciculata, Rusophycus dispar and Rusophycus burjensis are recorded along with Arenicolites isp. and Skolithos isp. from the Lower Quartzite Member. A rich and diverse ichnoassemblage attributed to the Cruziana ichnofacies is described for the first time from the Arkosic Sandstone Member of the same formation. Seven ichnofossil assemblages, i.e., Cruziana-Rusophycus, Planolites-Palaeophycus, Cruziana problematica, Diplichnites, Cochlichnus anguineus, Bergaueria perata and Psammichnites gigas have been recognized in the Lower Quartzite to Arkosic Sandstone members of the Koti Dhaman Formation. Seven sedimentary facies i.e., sandstone–shale facies (FT1), cross-bedded (trough and planar) sandstone (FT2), bedded sandstone facies (FT3), shale facies (FT4), shale–sandstone facies (FT5), shale-rippled sandstone facies (FT6) and planar and trough cross-laminated sandstone (FT7) and four facies associations FA1-FA4 are identified in the Koti Dhaman Formation. The formation contains shallowing upward parasequences of a tidal flat complex. Overall, two major events are recognized: i) the break in sedimentation between the Lower Quartzite Member and the overlying Shale Member probably related to forced-regressive event and ii) the facies shift from FT6 to FT7 of the Arkosic Sandstone Member represents an erosive transgressive event; the surface is interpreted as wave ravinement surface, which also serves as a sequence boundary. Integrated ichnology, sedimentology and sequence stratigraphic studies indicate that the Lower Quartzite Member was deposited in a shallow subtidal sand sheet complex and tidal flat complex; the Shale Member was deposited in a mud flat setting of a tidal flat complex, and the Arkosic Sandstone Member in a mixed-flat (tidal flat complex) to sand sheet complex front and margin (subtidal sand sheet complex). Overall, the lower to middle part of the Koti Dhaman Formation represents a tide-dominated shallow subtidal–intertidal to mud-flat subenvironments of the tidal flat complex. A palaeogeographic reconstruction of lower Cambrian (516–514?Ma) is presented based on the distribution of trilobite traces from the Lesser Himalaya and the Bikaner–Nagaur area of Peninsular India (eastern Gondwana), Egypt, Jordan, Turkey (western Gondwana) and Canada (Avalonia).  相似文献   

11.
A.H. Munshi 《Aerobiologia》2000,16(3-4):449-452
Several grass pollens are important environmental bio-pollutants, causing various allergic disorders in susceptible persons. Therefore, it is essential to study the period and duration of the flowering of the plants growing in a particular region/area. For the area Srinagar (Kashmir Himalaya), a flowering calendar of grasses consisting of 57 species which fall under 35 genera has been compiled in order to provide an understanding of habit, period of pollen release and their dispersal from the flowers, pollen load in the atmosphere and the influence of meterological parameters. The main object of this research work is to provide an information regarding the frequency of grass pollen in atmosphere to the physicians, or medical practitioners. The maximum flowering period is recorded from July to September. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

12.
New findings of Late Paleozoic and Triassic bryozoans from the Tethys Himalaya are reported. Fifteen species, including three undetermined, were described, while determinations at order, family or genus level were obtained on fragmentary material. The studied bryozoans were framed in a solid lithostratigraphic scheme spanning across the Tethys Himalaya for over 1500 km, from NW India (Zanskar and Spiti) through Nepal (Dolpo and Manang) to South Tibet; they are concentrated in correlatable stratigraphic intervals corresponding to the Upper Devonian-Tournaisian, Bashkirian, Sakmarian, Midian and Lower Norian. This study allowed us to integrate bryozoan occurrences reported from the literature, mostly referring to the Tournaisian, Bashkirian and Early Norian, and to refine the available biostratigraphic dates. Bryozoan-rich intervals are interpreted as associated to long-term transgressions, in turn driven by major climatic and/or tectonic events. Cosmopolitan genera which prevail in the Paleozoic, are replaced by provincial forms after the Triassic crisis.  相似文献   

13.
In higher plants, synaptic mutation-associated gametic abnormalities are reported mostly in crop plants, but studies have rarely focused on the natural plant populations. This is particularly so in threatened herbaceous perennials, some of which are known to suffer from loss of sexual reproduction driven by the genetic mutations. Cytological investigations of Panax species, viz. P. sikkimensis, P. sokpayensis and P. bipinnatifidus, revealed that all the species were diploid with 2n = 24 chromosomes. Natural occurrence of synaptic mutation was recorded in Panax sikkimensis in the Kalep population of North Sikkim, India. We recorded that 86.03% of pollen mother cells (PMCs) lacked bivalent formation and had 24 distinct univalents at prophase I in the mutant plants of P. sikkimensis. We found a significantly lower mean number of chiasmata per cell (0.31 ± 0.91; t test = 38.24, P < 0.001) in the mutant plants as compared to the normal plants (21.04 ± 4.56). The chromosomal associations in the PMCs of the synaptic mutants ranged from 25% bivalents and 75% univalents to 100% univalents at diplotene/diakinesis. The unequal distribution of chromosomes at anaphase I and II resulted in the formation of microspores and microcytes of differing sizes. The pollen stainability test in the mutant population of P. sikkimensis revealed very low (0.12%) pollen fertility reflecting the consequences of synaptic mutation. Synaptic mutation in the herbaceous perennial P. sikkimensis was considered to be responsible for the male sterility in the species.  相似文献   

14.
Forage selection decisions of herbivores are often complex and dynamic; they are modulated by multiple cues, such as quality, accessibility and abundance of forage plants. To advance the understanding of plant–herbivore interactions, we explored foraging behavior of the alpine lagomorph Royle's pika (Ochotona roylei) in Kedarnath Wildlife Sanctuary, India. Pika bite counts on food plants were recorded through focal sampling in three permanently marked plots. Food plant abundance was recorded by traditional quadrat procedures; forage selection was estimated with Jacob's selection index. Multiple food-choice experiments were conducted to determine whether forage selection criteria would change with variation in food plant composition. We also analyzed leaf morphology and nutrient content in both major food plants and abundantly available non-food plants. Linear regression models were used to test competing hypotheses in order to identify factors governing forage selection. Royle's pika fed primarily on 17 plant species and each forage selection decision was positively modulated by leaf area and negatively modulated by contents of avoided substances (neutral detergent fiber, acid detergent fiber, acid detergent lignin and tannin) in food plants. Furthermore, significance of the interaction term “leaf size × avoided substance” indicates that plants with large leaves were selected only when they had low avoided substance content. The forage selection criteria did not differ between field and laboratory experiments. The parameter estimates of best fit models indicate that the influence of leaf size or amount of avoided substance on pika forage selection was modulated by the magnitude of predation risk.  相似文献   

15.
16.
The affinity of the Ediacaran fossil Shaanxilithes ningqiangensis and putatively related forms has long been enigmatic; over the past few decades, interpretations ranging from trace fossils to algae to metazoans of uncertain phylogenetic placement have been proposed. Combined morphological and geochemical evidence from a new occurrence of S. ningqiangensis in the Krol and Tal groups of the Lesser Himalaya of India indicates that S. ningqiangensis is not a trace fossil, but rather an organic‐walled tubular body fossil of unknown taxonomic affinity. Specimens consist of compressed organic cylindrical structures, characterized by extended, overlapping or fragmented iterated units. Where specimens intersect, overlapping rather than branching or intraplanar crossing is observed. Lithologic comparisons and sequence stratigraphic data all suggest a late Ediacaran age for the uppermost Krol Group and basalmost Tal Group. By extending the biogeographical distribution of S. ningqiangensis, hitherto confined to the Ediacaran of China and potentially Siberia, to the Precambrian–Cambrian boundary interval of India, this new occurrence of S. ningqiangensis expands the biostratigraphic utility of this enigmatic fossil to the inter‐regional and intercontinental scale. Moreover, study of these new and exceptionally preserved samples may help to significantly constrain the long‐debated problem of Shaanxilithes' affinity, elucidating its ‘problematic’ status and shedding new light upon the ecology and taphonomy of one of the most significant intervals in early life history.  相似文献   

17.
《Palaeoworld》2020,29(3):490-511
An assemblage of organic walled microfossils (OWM) of 17 taxa belonging to 10 genera is reported from the Neoproterozoic Owk Shale of the Kurnool Group, South India. The assemblage comprises sphaeromorphs, colonial aggregates, filamentous forms, spiral cylindrical filaments belonging to cyanobacteria, problematic acanthomorphic acritarchs, Netromorphic, Sphaeromorphic and Acantomorphic groups. The assemblage includes cyanobacteria: Siphonophycus kestron, S. robustum, S. typicum, S. solidum, Polytrichoides lineatus; Netromorphic acritarch: Arctacellularia tetragonala, Navifusa majensis, Jacutianema solubila; Sphaeromorphic acritarch: Ostiana microcystis, Synsphaeridium spp., Leiosphaeridia minutissima, L. tenuissima, L. crassa, L. jacutica, L. ternate; and Acanthomorphic acritarch: Cavaspina aff. C. acuminata and Variomargosphaeridium aff. V. litoschum. The age conundrum of Kurnool Group (Mesoproterozoic versus Neoproterozoic) is discussed. On the basis of the reported OWM assemblage the age of the Kurnool Group is established as Neoproterozoic.  相似文献   

18.
The new species Picrorhiza tungnathii Pusalkar is described and illustrated from the western Himalaya, India. It is distinguished from the allied P. kurrooa Royle ex Benth. by being 10–25 cm tall, having a moderately dense, (10–)15–25‐flowered spike, a zygomorphic, 2‐lipped, glandular‐ciliate corolla that is equaling or slightly exceeding the calyx and partly visible or sub‐exserted between the calyx lobes, a conspicuously long (longer than the corolla lobes), curved corolla tube (1/2–4/5 the length of the calyx), unequal corolla lobes that are ovate‐lanceolate to lanceolate, acute to sub‐acuminate and moderately ciliate, a mid‐lobe of the upper lip that is obliquely erect, galeate with retuse or emarginate apex, lateral corolla lobes that are slightly smaller than the mid‐lobe of the upper lip, a lower corolla lip that is slightly shorter than the lateral lobes, obliquely erect or spreading, didynamous, long‐exserted (2–3 times the corolla) stamens, pollen of the Paederota‐type and a style that is 2–3 times as long as the corolla.  相似文献   

19.
A fossil Lagerstätte from the 700–750 Ma old Svanbergfjellet Formation of northeastern Spitsbergen offers a substantially enhanced view of late Proterozoic paleobiology. Fossils occur primarily as Organic-walled compressions in shales and permineralizations in chert: secondary modes of preservation include bedding-plane imprints and mineral replacements in apatite and goethite (?). The depositional setting of all fossiliferous horizons is broadly peritidal with highest taxonomic diversity occurring in shallow subtidal settings; the details of included fossil assemblages contribute to improved paleoecological resolution. The often distinct constituents of shale-and chert-hosted fossil assemblages appear to be a product of both paleoenvironment and fundamentally dissimilar taphonomic pathways, such that only forms with inferred wide ecological tolerance appear in both. Consideration of taphonomic processes also provides a variety of useful taxonomic insights, on the one hand permitting some resolution of so-called wastebasket taxa. such as Chuaria, and on the other acknowledging the taxonomic disparity that can occur in simple forms like Siphonophycus and Oscillatoriopsis. True multicellular (including coenocytic) eukaryotes are a conspicuous Component of the Svanbergfjellet assemblage: of eight distinct taxa, one can be identified as a coenobial/colonial chlorococcalean and three as filamentous siphonocladaleans (Chlorophyta). Other forms are problematic, but several show significant cell, or possibly tissue, differentiation. A review of Proterozoic multicellular organisms reveals that a coenocytic grade of organization was common among early metaphytes and supports the view (that a cellularity is a derived condition in many ‘multicellular’ lineages. Nineteen acritarch taxa are preserved in the Svanbergfjellet sediments. Ten of these show a readily identifiable ornamentation and contribute significantly to Neoproterozoic biostratigraphy; a world-wide and exclusively Late Riphean distribution of the acanthomorph Trachyhystrichosphaera aimika identifies it as a particularly valuable index fossil. The Svanbergfjellel fossil assemblage preserves a total of 63 distinct forms, of which 56 are treated taxonomically. As much as possible, principles of ‘natural’ taxonomy are applied, such that taphonomic and ontogenetic variants are declined separate taxonomy status. Major taxonomic revisions are offered for the acritarchs Trachyhystrichosphaera and Chuaria as well as for the prokaryotic-grade filaments: Cephalonyx, Cyanonema, Oscillatoriopsis, Palaeolyngbya, Rugossopsis, Siphonophycus, Tortunema, and Veteronostocale. Newly erected taxa include 7 new genera: Palaeastrum. Proterocladus, Pseudotawuia, Valkyria, Cerebrosphaera, Osculosphera and Pseudodendron; 14 new species in 12 genera: Palaestrum ***dyptocranum, Proterocladus major, Proterocladus minor, Proterocladus ***hermannae. Pseudodendron birenifera, Valkyria borealis, Cerebrosphaera buickii, Osculosphaera hyaline, Pseudodendron anteridium fullerne, Germinosphaera jankauskasii, Trachyhystrichosphaera polaris, Siphonophycus thulenema and thulenema and Digitus adumbrates 7 new combinations: Leiosphaeridia wimanii, Eoentophysalis croxfordii Cephlonyx geminatus. Oscillatoriopsis amadeus. Siphonophycus typicum, Siphonophycus solidum and Tortunema Wernadskii.  相似文献   

20.
A new species of Gentianella, G. tumailica sp. nov., from Tumail in the Kargil district of Ladakh, northwest Himalaya, India is described and illustrated. This novelity is morphologically similar to the sympatric G. stoliczka in inflorescence pattern, calyx and corolla shapes, sagitate anthers, more or less rounded seeds, but differs in smaller size of vegetative and floral structures, larger basal leaves, few cauline leaves, leaf apex obtuse to rounded, calyx lobes unequal (2 longer, 3 shorter), inflorescence enveloped by 4 foliaceous bracts, capsule elliptic to oblong and seed coat smooth. In addition, a diagnostic key to all Indian species of Gentianella is presented.  相似文献   

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