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1.
This paper documents the first record of silicified fossil wood from a previously undescribed wood-rich horizon in the Sitakund Anticline, Eastern Bangladesh. The outcrop is composed of cross-stratified, fine-medium grained sandstones with bidirectional cross stratification indicative of a tidal environment, deposited ca. 5-5.2 million years before present (Miocene/Pliocene). The wood is characterised by large solitary vessels with alternate intervascular pits, banded parenchyma, uniseriate rays, and multiseriate rays with one radial canal per ray. This character combination closely resembles the wood of extant Gluta L. of the Anacardiaceae. This specimen has been assigned to the organ genus Glutoxylon Chowdhury erected for fossil woods with anatomical similarity to Gluta (including Melanorrhoea Wall.). The excellent preservation of this mature wood specimen illustrates the potential for using fossil wood from the Sitakund locality for palaeoecological studies in terms of biodiversity and adaptational response to climate change. Moreover such investigations of fossil woods from Bangladesh will compliment studies undertaken on fossil plants in other parts of Central and Southeastern Asia which will further the understanding of plant migration routes between India and Southeast Asia during the Tertiary.  相似文献   

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New species of the Pinaceae, Abies chavchavadzeae and Piceoxylon ussuriense, are described on the basis of fossil woods from the Pliocene of the Pavlovka lignite field (southern Primorye). For the first time, fossil wood of Abies is reported from the Russian Far East.  相似文献   

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Huber JT  Greenwalt D 《ZooKeys》2011,(130):473-494
Compression fossils of three genera and six species of Mymaridae (Hymenoptera: Chalcidoidea) are described from 46 million year old Kishenehn oil shales in Montana, USA. Two new genera are described: Eoeustochus Huber, gen. n., with two included species, Eoeustochus kishenehn Huber (type species) and Eoeustochus borchersi Huber, sp. n., and Eoanaphes, gen. n., with Eoanaphes stethynioides Huber, sp. n. Three new species of Gonatocerus are also described, Gonatocerus greenwalti Huber, sp. n. , Gonatocerus kootenai Huber, sp. n., and Gonatocerus rasnitsyni Huber, sp. n. Previously described amber fossil genera are discussed and five genera in Baltic amber are tentatively recorded as fossils: Anagroidea, Camptoptera, Dorya, Eustochus, and Mimalaptus.  相似文献   

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通过形态学和分子生物学分析,实验菌株为药用拟层孔菌。采用不同有机溶剂提取药用拟层孔菌子实体,分别获得石油醚、氯仿、乙酸乙酯和甲醇提取物。采用GC-MS方法,分析药用拟层孔菌石油醚提取物中的化学成分,同时对不同有机溶剂提取物的生物活性进行检测。结果表明:药用拟层孔菌石油醚提取物中共鉴定出46个化合物。体外抑制肿瘤细胞活性实验表明,在100μg/m L时,不同有机溶剂提取物都表现出抑制肿瘤细胞活性。其中,石油醚提取物在50μg/m L时,其对NCI-H460和SGC-7901肿瘤细胞的抑制率分别为99.03%和82.57%。甲醇提取物在8mg/m L时,DPPH自由基清除率达93.35%。  相似文献   

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During the early Eocene (~55–52 Ma), when the Indian subcontinent relished equatorial climatic conditions, lignite was deposited along its north western margin. Lignite mines of northwestern India have proved to be an outstanding resource for palaeoenvironmental information. The Vastan lignite mine of the early Eocene age situated near Surat district (Gujarat) is one of the well-dated and fossiliferous lignite mines in western India. A fossil wood, retrieved from this mine, is systematically described and shows a strong resemblance to the modern genus Chisocheton of the family Meliaceae. Plant fossils are the best source to reconstruct the palaeoenvironment of any region, and here a luxurious, highly diverse tropical evergreen forest is interpreted in and around the fossil locality in contrast to the tropical thorn forest of the present day. This early Eocene highly diverse equatorial forest, once covered a significant portion of the Indian subcontinent, is now restricted in fringes known as Western Ghats in south India attesting to changes in climate.  相似文献   

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In this article we describe the microscopic structures of a silicified piece of wood collected in the Middle Awash Valley (Ethiopia). The fossil wood was extracted from sediment precisely dated 4.4 Ma. Its attribution to the Ficoxylon species is based upon detailed comparison with published data and with comparisons of some modern species of the genus Ficus and similar characters encountered in fossil woods from West Africa, Egypt, Libya and Ethiopia previously described and attributed to this taxon.  相似文献   

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Neem (Azadirachta indica) extract (NE) and NE combined with copper sulfate and boric acid (NECB) were examined for their protective effect against fungal deterioration of mango (Mangifera indica) and rain tree (Albizia saman) wood. Growth of the white-rot fungus Schizophyllum commune was completely inhibited on solid medium containing 1.8% (w/w) NE or 5% (w/w) NECB. The average weight losses of NE and NECB treated wood blocks inoculated with S. commune were respectively 4.7% and 3.3% for M. indica and 4.1% and 3.0% for A. saman. These numbers were significantly lower compared to those obtained in the untreated condition. Similar observations were also noticed in the case of field tests. An average increase of life span of M. indica and A. saman due to NE treatment compared to untreated samples was about 6–7 times higher. Therefore, both NE and NECB treatments are promising preservation options for enhancing the durability of both M. indica and A. saman woods.  相似文献   

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The wood of the plant Sesbania sesban, is reported to have antinociceptive activity. To validate its folk use in the treatment of pain, wood was extracted successively with petroleum ether, chloroform, ethyl acetate, ethanol, and water to produce respective extracts. The extracts (50 and 100 mg/kg, ip) were screened for antinociceptive activity using hot plate test and acetic acid-induced writhing test in mice. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose-dependent activity in both the tests. In order to find out the involvement of opioid receptors, effect of naloxone (1 mg/kg, sc) on the action of extracts was checked in hot plate test. Petroleum ether, chloroform, and ethyl acetate extracts showed significant and dose dependant antinociceptive activity. The antinociceptive action of the extracts was blocked by naloxone, suggesting involvement of opioid receptors in the action.  相似文献   

10.
Summary The reproducibility of EUF-Ca, K, Na, P, B, NO3–N and EUF extractable N for fraction 1 (200 V, 20° C, 30 minutes) was within a CV range of 4.54–12.28%.The summation of results for fraction 1 (200 V, 20°C, 30 minutes) and fraction 2 (400 V, 80°C, 5 minutes) gave an improved CV range of 4.23–8.81%.EUF-Mg obtained from fraction 1 (200 V, 20°C, 30 minutes), fraction 2 (400 V, 80°C, 5 minutes) and the acid fraction gave a CV of 6.81%.Results from the acid fraction gave poor reproducibility for Zn, (CV=45.1%). The CV of 12.5% for Mn is low compared to the CV of 30–40% usually obtained.The recovery of Zn, Mn and Mg from the acid fraction was improved. The reproducibility of Zn and Mg was also improved by (a) reducing the sources of contamination; (b) introducing a second filter at the cathode; (c) steeping the filters for 48 hours.  相似文献   

11.
The mechanism of wood development records in varying degree the effects of both external and internal factors that are operating at the time of development. As a result, fossil woods spanning the last 370 million years represent a unique palaeo-environmental data-store. Data concerning external factors that can be reclaimed consist of: presence or absence of growth rings; ring widths; relative proportions of earlywood and latewood and the nature of the transition between them; “false” and “frost” rings and evidence of damage by animals or fire; occurrence of reaction wood. These effects have to be seen against a background of the influences of the internal factors. The development of wood involves the action of plant growth regulators. The production of an entire season’s growth of wood depends on a supply of photosynthate, partly stored from the previous year, and the remainder directly from photosynthesis during the current one. In any population of trees of the same species there will be genetic variation which will lead to differences in the wood formed by the individual trees even if they have all grown in a largely similar environment. However the external factors exert a much greater influence than the internal ones. Our earliest fossil woods (Upper Devonian) show either seasonless growth patterns or, if weak rings are perceptible, then the increments are extensive. This is consistent with the palaeo-equatorial position of all recorded Devonian woods. In the Carboniferous a few sites (marginal in the tropical belt?) show subdued (weak) growth rings. By the time of the Gondwana glaciation strong rings are shown in high southern latitudes, but most surprisingly there are sizeable increments well inside the palaeoantarctic circle. This phenomenon persists into the Mesozoic where lack of growth rings shows consistency with positions within the palaeo-equatorial latitudes. However occurrence of Cretaceous high latitude wood growth demonstrates that given an adequate ambient temperature, forest growth was possible close to both poles. It is shown that this is consistent with the total energy flux known to occur now in high latitudes.  相似文献   

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The cave of Artenac is located about 20 km northeast of Angouleme, in the commune of Saint-Mary (Charente). In 1995 and 1996, two fragmentary hominine skull bones, a maxilla and a frontal, were uncovered during excavations in Mousterian levels of the cave. Biostratigraphic analyses of the abundant mammalian fauna place the Mousterian occupation of the cave at the beginning of Oxygen Isotope Stage 5. Although both bones come from adults, aspects of their morphology indicate they could derive from two individuals of different ages at death. The two bones are relatively fragmentary, but sufficient detail has been preserved, including an inflated maxillary region lacking an infra-orbital depression (or fossa canina) and the shape of the forehead, to establish their identity as Neandertals.  相似文献   

15.
A new species, Chadronoxylon sakhalinensis sp. nov. (Angiospermae, Dicotyledones), from the Upper Cretaceous of Sakhalin (Russian Far East) is described based on the anatomical characters of fossil wood. The fossil wood of Chadronoxylon is found in Russia for the first time.  相似文献   

16.
The petroleum ether, chloroformic, ethyl acetate, methanolic, Total Oligomers Flavonoids (TOF) enriched extracts, water extract as well as its fractions A1, A2, A3 obtained from aerial parts ofRhamnus alaternus, a Tunisian-Mediterranean medicinal species, were investigated for the contents of phenolic compounds, cytotoxic activity against the K562 human chronic myelogenous leukaemia cell line and L1210 leukaemia murine cells and for antibacterial activity against Gram positive and Gram negative bacterial reference strains. A pronounced cytotoxic effect on both the cell lines was shown in the TOF, ethyl acetate, methanolic, aqueous extracts and A2 fraction, with respectively IC50 values 75, 232, 298, 606 and 571 μg/ml on K562 cells and 198, 176, 767, 560 and 614 μg/ml on L1210 cell line. Significant activity against bacterial reference strains:Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella enteritidis andSalmonella typhimurium was shown with ethyl acetate, TOF extracts and A2 fraction. The antimicrobial and cytotoxic activities showed byR. alatemus depended on the chemical composition of the tested extracts.  相似文献   

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Smith ND 《PloS one》2010,5(10):e13354

Background

Debate regarding the monophyly and relationships of the avian order Pelecaniformes represents a classic example of discord between morphological and molecular estimates of phylogeny. This lack of consensus hampers interpretation of the group''s fossil record, which has major implications for understanding patterns of character evolution (e.g., the evolution of wing-propelled diving) and temporal diversification (e.g., the origins of modern families). Relationships of the Pelecaniformes were inferred through parsimony analyses of an osteological dataset encompassing 59 taxa and 464 characters. The relationships of the Plotopteridae, an extinct family of wing-propelled divers, and several other fossil pelecaniforms (Limnofregata, Prophaethon, Lithoptila, ?Borvocarbo stoeffelensis) were also assessed. The antiquity of these taxa and their purported status as stem members of extant families makes them valuable for studies of higher-level avian diversification.

Methodology/Principal Findings

Pelecaniform monophyly is not recovered, with Phaethontidae recovered as distantly related to all other pelecaniforms, which are supported as a monophyletic Steganopodes. Some anatomical partitions of the dataset possess different phylogenetic signals, and partitioned analyses reveal that these discrepancies are localized outside of Steganopodes, and primarily due to a few labile taxa. The Plotopteridae are recovered as the sister taxon to Phalacrocoracoidea, and the relationships of other fossil pelecaniforms representing key calibration points are well supported, including Limnofregata (sister taxon to Fregatidae), Prophaethon and Lithoptila (successive sister taxa to Phaethontidae), and ?Borvocarbo stoeffelensis (sister taxon to Phalacrocoracidae). These relationships are invariant when ‘backbone’ constraints based on recent avian phylogenies are imposed.

Conclusions/Significance

Relationships of extant pelecaniforms inferred from morphology are more congruent with molecular phylogenies than previously assumed, though notable conflicts remain. The phylogenetic position of the Plotopteridae implies that wing-propelled diving evolved independently in plotopterids and penguins, representing a remarkable case of convergent evolution. Despite robust support for the placement of fossil taxa representing key calibration points, the successive outgroup relationships of several “stem fossil + crown family” clades are variable and poorly supported across recent studies of avian phylogeny. Thus, the impact these fossils have on inferred patterns of temporal diversification depends heavily on the resolution of deep nodes in avian phylogeny.  相似文献   

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Eohomopterus simojovelensis n. sp., the first fossil record of the subfamily Paussinae (Coleoptera: Carabidae) from the Miocene amber of the Simojovel area, Chiapas, Mexico, is described. The morphology of the new species is compared withEohomopterus poinari Nagel, 1997 from Dominican amber as well as with extant representatives ofEohomopterus, and the biogeographical implications are discussed.   相似文献   

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