Journal articles on the topic 'Angiosperms'
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1
Wang, Xin. "A Novel Early Cretaceous Flower and Its Implications on Flower Derivation." Biology 11, no. 7 (July 11, 2022): 1036. http://dx.doi.org/10.3390/biology11071036.
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Background: The origin and early evolution of angiosperms, by far the most important plant group for human beings, are questions demanding answers, mainly due to a lack of related fossils. The Yixian Formation (Lower Cretaceous) is famous for its fossils of early angiosperms, and several Early Cretaceous angiosperms with apocarpous gynoecia have been documented. However, a hypanthium and an inferior ovary are lacking in these fossil angiosperms. Methods: The specimen was collected from the outcrop of the Yixian Formation in Dawangzhangzi in the suburb of Lingyuan, Liaoning, China. The specimen was photographed using a Nikon D200 digital camera, and its details were photographed using a Nikon SMZ1500 stereomicroscope and a MAIA3 TESCAN SEM. Results: A fossil angiosperm, Lingyuananthus inexpectus gen. et sp. nov, is reported from the Lower Cretaceous of China. Differing from those documented previously, Lingyuananthus has a hypanthium, an inferior ovary, and ovules inside its ovary. Such a character assemblage indicates its angiospermous affinity, although not expected by any existing leading angiosperm evolutionary theory. Conclusions: New fossil material with a unique character assemblage falls beyond the expectation of the currently widely accepted theories of angiosperm evolution. Together with independently documented fossils of early angiosperms, Lingyuananthus suggests that at least some early angiosperms’ flowers can be derived in a way that has been ignored previously.
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Friis, Else Marie, Peter R. Crane, Kaj Raunsgaard Pedersen, Mário Miguel Mendes, and Jiří Kvaček. "The Early Cretaceous mesofossil flora of Catefica, Portugal: angiosperms." Fossil Imprint 78, no. 2 (2022): 341–424. http://dx.doi.org/10.37520/fi.2022.016.
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Angiosperm mesofossils are described from the Lower Cretaceous Almargem Formation exposed near the village of Catefica, Portugal, and are thought to be of Aptian-early Albian age. The mesofossil assemblage from Catefica is diverse and, in addition to the angiosperms described here, also contains a rich assemblage of non-angiosperm fossils, including leafy axes of bryophytes and lycopsids, lycopsid and salvinialean megaspores, and sporangia, sori and leaf fragments of ferns. There are also twigs, cones, cone scales, seeds and sporangia of several kinds of conifers. Other seed plants include 11 species of chlamydospermous seeds and vegetative axes related to the BEG group (Bennettiales-Erdtmanithecales-Gnetales). In terms of the number of plant fragments identified, angiosperms are most abundant in the Catefica assemblage and account for more than half of all specimens. Angiosperms also dominate in number of species, but because the non-angiosperm fossils have not been studied in detail the total number of species in the flora is not yet established. Sixty-seven species of angiosperms are recognized. Angiosperm diversity is mainly at the level of non-eudicots, including ANA-grade angiosperms, Chloranthaceae and magnoliids. Remains of chloranthoid angiosperms are especially common, both in the number of specimens and in number of species recognized. About 40 % of the specimens, and more than 25 % of the species are chloranthoids. Remains of magnoliid angiosperms (Magnoliales, Laurales, Canellales, Piperales) are also prominent among the angiosperms. Eudicots are subordinate: only 3–4 % of all angiosperm specimens can be assigned confidently to eudicot angiosperms. Five new genera and six new species of angiosperms are established (Canrightia foveolata sp. nov., Elasmostemon paisii gen. et sp. nov., Endressistemon cateficensis gen. et sp. nov., Ibericarpus cuneiformis gen. et sp. nov., Proencistemon portugallicus gen. et sp. nov., Valvidistemon globiferus gen. et sp. nov.). Several other new taxa are also described, but not formally named.
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Feild, Taylor S., Garland R. Upchurch, David S. Chatelet, Timothy J. Brodribb, Kunsiri C. Grubbs, Marie-Stéphanie Samain, and Stefan Wanke. "Fossil evidence for low gas exchange capacities for Early Cretaceous angiosperm leaves." Paleobiology 37, no. 2 (2011): 195–213. http://dx.doi.org/10.1666/10015.1.
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The photosynthetic gas exchange capacities of early angiosperms remain enigmatic. Nevertheless, many hypotheses about the causes of early angiosperm success and how angiosperms influenced Mesozoic ecosystem function hinge on understanding the maximum capacity for early angiosperm metabolism. We applied structure-functional analyses of leaf veins and stomatal pore geometry to determine the hydraulic and diffusive gas exchange capacities of Early Cretaceous fossil leaves. All of the late Aptian—early Albian angiosperms measured possessed low vein density and low maximal stomatal pore area, indicating low leaf gas exchange capacities in comparison to modern ecologically dominant angiosperms. Gas exchange capacities for Early Cretaceous angiosperms were equivalent or lower than ferns and gymnosperms. Fossil leaf taxa from Aptian to Paleocene sediments previously identified as putative stem-lineages to Austrobaileyales and Chloranthales had the same gas exchange capacities and possibly leaf water relations of their living relatives. Our results provide fossil evidence for the hypothesis that high leaf gas exchange capacity is a derived feature of later angiosperm evolution. In addition, the leaf gas exchange functions of austrobaileyoid and chloranthoid fossils support the hypothesis that comparative research on the biology of living basal angiosperm lineages reveals genuine signals of Early Cretaceous angiosperm ecophysiology.
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Doyle, James A. "Significance of molecular phylogenetic analyses for paleobotanical investigations on the origin of angiosperms." Journal of Palaeosciences 50, no. (1-3) (December 31, 2001): 167–88. http://dx.doi.org/10.54991/jop.2001.1821.
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Molecular phylogenetic analyses have provided increasing evidence that angiosperms are not related to Gnetales, thus contradicting the anthophyte hypothesis based on morphological cladistic analyses and throwing the question of angiosperm relatives back to paleobotanists. Previous analyses of gene sequences based on a molecular clock conflicted with the fossil record in indicating a Late Palaeozoic or Triassic origin of the angiosperms, but closer examination suggests that these dates were biased by the use of herbaceous taxa with accelerated rates of molecular evolution. Despite uncertainty on angiosperm relatives, analyses of many genes consistently place Amborella, Nymphaeales, Austrobaileya, Trimenia and Illiciales (the ‘ANITA grade') at the base of extant angiosperms, possibly followed by Chloranthaceae. Molecular phylogenies imply that the first crown-group angiosperms had columellar exine structure, suggesting that Hauterivian-Barremian reticulate-columellar monosulcates may be closer to the origin of angiosperms than was thought when granular Magnoliales were believed to be basal. Hauterivian pollen with a verrucate tectum and microspinules is especially similar to Amborella. The ANITA lines and Chloranthaceae have ascidiate carpels sealed by secretion and often exotestal seeds, fitting the abundance of such carpels and seeds in Barremian-Aptian mesofloras. Similarities between Aptian angiosperm leaves and ANITA taxa, such as chloranthoid teeth and variable stomatal structure, also suggest that Early Cretaceous angiosperms were more primitive than previously appreciated. Molecular results may help refine search images for extinct angiosperm relatives, away from Gnetales and toward groups such as Caytonia, Glossopterids, Bennettitales and Corystosperms. Since molecular data place the vesselless taxa Amborella and Nymphaeales at the base of the angiosperms, the presence of vessels is not evidence that gigantopterids are related to angiosperms. The conclusion that columellar structure is ancestral reaffirms the potential of Triassic reticulate-columellar Crinopolles pollen as angiosperm relatives.
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Sun Ge and D. L. Dilcher. "Early angiosperms from Lower Cretaceous of Jixi, China and their significance for study of the earliest occurrence of angiosperms in the world." Journal of Palaeosciences 45 (December 31, 1996): 393–99. http://dx.doi.org/10.54991/jop.1996.1260.
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This paper reports the recent study of the earliest known angiosperms in the world found from the Lowe Cretaceous of Jixi, China, and first demonstrates the general information on the oldest known Inflorescences Xingxueina heilongfiangensis Sun et Dilcher (MS) contained in the Jixi early angiosperms. The inflorescences possess numerous pollens in situ, very small, inaperturate and tectate-columellate in exine, and can be compared to those from Valanginian-Hauterivian of Israel studied by Brenner (1995). Based on the comparison and on the marine beds, yielding Valanginian-Hauterivian dinoflagellates, underlying conformably the angiosperm-bearing beds the Jixi angiosperms are considered Hauterivian or Hauterivian-Early Barremian in age. The paper has also discussed the findings of the angiosperm-like or questionable angiosperm material newly from China and previously from Mongolia, proposed there might exist an original centre of angiosperms in East Asia. However, it would not be excluded that there were two original centres (East Asia and Eastern Gondwanaland) where the earliest angiosperms evolved and developed in parallel during the early time of Early Cretaceous.
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Lee, Alexandra P., Garland Upchurch, Erik H. Murchie, and Barry H. Lomax. "Leaf energy balance modelling as a tool to infer habitat preference in the early angiosperms." Proceedings of the Royal Society B: Biological Sciences 282, no. 1803 (March 22, 2015): 20143052. http://dx.doi.org/10.1098/rspb.2014.3052.
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Despite more than a century of research, some key aspects of habitat preference and ecology of the earliest angiosperms remain poorly constrained. Proposed growth ecology has varied from opportunistic weedy species growing in full sun to slow-growing species limited to the shaded understorey of gymnosperm forests. Evidence suggests that the earliest angiosperms possessed low transpiration rates: gas exchange rates for extant basal angiosperms are low, as are the reconstructed gas exchange rates for the oldest known angiosperm leaf fossils. Leaves with low transpirational capacity are vulnerable to overheating in full sun, favouring the hypothesis that early angiosperms were limited to the shaded understorey. Here, modelled leaf temperatures are used to examine the thermal tolerance of some of the earliest angiosperms. Our results indicate that small leaf size could have mitigated the low transpirational cooling capacity of many early angiosperms, enabling many species to survive in full sun. We propose that during the earliest phases of the angiosperm leaf record, angiosperms may not have been limited to the understorey, and that some species were able to compete with ferns and gymnosperms in both shaded and sunny habitats, especially in the absence of competition from more rapidly growing and transpiring advanced lineages of angiosperms.
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Friis, Else Marie, Kaj Raunsgaard Pedersen, and Peter R. Crane. "Diversity in obscurity: fossil flowers and the early history of angiosperms." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1539 (February 12, 2010): 369–82. http://dx.doi.org/10.1098/rstb.2009.0227.
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In the second half of the nineteenth century, pioneering discoveries of rich assemblages of fossil plants from the Cretaceous resulted in considerable interest in the first appearance of angiosperms in the geological record. Darwin's famous comment, which labelled the ‘rapid development’ of angiosperms an ‘abominable mystery’, dates from this time. Darwin and his contemporaries were puzzled by the relatively late, seemingly sudden and geographically widespread appearance of modern-looking angiosperms in Late Cretaceous floras. Today, the early diversification of angiosperms seems much less ‘rapid’. Angiosperms were clearly present in the Early Cretaceous, 20–30 Myr before they attained the level of ecological dominance reflected in some mid-Cretaceous floras, and angiosperm leaves and pollen show a distinct pattern of steadily increasing diversity and complexity through this interval. Early angiosperm fossil flowers show a similar orderly diversification and also provide detailed insights into the changing reproductive biology and phylogenetic diversity of angiosperms from the Early Cretaceous. In addition, newly discovered fossil flowers indicate considerable, previously unrecognized, cryptic diversity among the earliest angiosperms known from the fossil record. Lineages that today have an herbaceous or shrubby habit were well represented. Monocotyledons, which have previously been difficult to recognize among assemblages of early fossil angiosperms, were also diverse and prominent in many Early Cretaceous ecosystems.
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Bateman, Richard M. "Hunting the Snark: the flawed search for mythical Jurassic angiosperms." Journal of Experimental Botany 71, no. 1 (September 20, 2019): 22–35. http://dx.doi.org/10.1093/jxb/erz411.
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Abstract Several recent palaeobotanical studies claim to have found and described pre-Cretaceous angiosperm macrofossils. With rare exceptions, these papers fail to define a flower, do not acknowledge that fossils require character-based rather than group-based classification, do not explicitly state which morphological features would unambiguously identify a fossil as angiospermous, ignore the modern conceptual framework of phylogeny reconstruction, and infer features in the fossils in question that are interpreted differently by (or even invisible to) other researchers. This unfortunate situation is compounded by the relevant fossils being highly disarticulated two-dimensional compression-impressions lacking anatomical preservation. Given current evidence, all supposed pre-Cretaceous angiosperms are assignable to other major clades among the gymnosperms sensu lato. By any workable morphological definition, flowers are not confined to, and therefore cannot delimit, the angiosperm clade. More precisely defined character states that are potentially diagnostic of angiosperms must by definition originate on the phylogenetic branch that immediately precedes the angiosperm crown group. Although the most reliable candidates for diagnostic characters (triploid endosperm reflecting double fertilization, closed carpel, bitegmic ovule, and phloem companion cells) are rarely preserved and/or difficult to detect unambiguously, similar characters have occasionally been preserved in high-quality permineralized non-angiosperm fossils. The angiosperm radiation documented by Early Cretaceous fossils involves only lineages closely similar to extant taxonomic families, lacks obvious morphological gaps, and (as agreed by both the fossil record and molecular phylogenies) was relatively rapid—all features that suggest a primary radiation. It is unlikely that ancestors of the crown group common ancestor would have fulfilled a character-based definition of (and thereby required expansion of the concept of) an angiosperm; they would instead form a new element of the non-angiosperm members of the ‘anthophyte’ grade, competing with Caytonia to be viewed as morphologically determined sister group for angiosperms. Conclusions drawn from molecular phylogenetics should not be allowed to routinely constrain palaeobotanical inferences; reciprocal illumination between different categories of data offers greater explanatory power than immediately resorting to Grand Syntheses. The Jurassic angiosperm—essentially a product of molecular phylogenetics—may have become the holy grail of palaeobotany but it appears equally mythical.
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Lusk, Christopher H., Mylthon Jiménez-Castillo, and Nicolás Salazar-Ortega. "Evidence that branches of evergreen angiosperm and coniferous trees differ in hydraulic conductance but not in Huber values." Canadian Journal of Botany 85, no. 2 (January 2007): 141–47. http://dx.doi.org/10.1139/b07-002.
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The hydraulic efficiency conferred by vessels is regarded as one of the key innovations explaining the historical rise of the angiosperms at the expense of the gymnosperms. Few studies, however, have compared the structure and function of xylem and their relationships with foliage traits in evergreen representatives of both groups. We measured sapwood cross-sectional area, conduit diameters, hydraulic conductance, and leaf area of fine branches (2.5–7.5 mm diameter) of five conifers and eight evergreen angiosperm trees in evergreen temperate forests in south-central Chile. Conductance of both lineages was higher at Los Lleuques, a warm temperate site with strong Mediterranean influence, than in a cool temperate rain forest at Puyehue. At a common sapwood cross-sectional area, angiosperm branches at both sites had greater hydraulic conductance (G) than conifers, but similar leaf areas. Branch conductance normalized by subtended leaf area (GL) at both sites was, therefore, higher in angiosperms than in conifers. Hydraulically weighted mean conduit diameters were much larger in angiosperms than in conifers, although this difference was less marked at Puyehue, the cooler of the two sites. Conduits of the vesselless rain forest angiosperm Drimys winteri J.R. & G. Forst were wider than those of coniferous associates, although narrower than angiosperm vessels. However, GL of D. winteri was within the range of values measured for vesselbearing angiosperms at the same site. The observed differences in xylem structure and function correlate with evidence that evergreen angiosperms have higher average stomatal conductance and photosynthetic capacity than their coniferous associates in southern temperate forests. Comparisons of conifers and angiosperm branches thus suggest that the superior capacity of angiosperm conduits is attributable to the development of higher gas-exchange rates per unit leaf area, rather than to a more extensive leaf area. Results also suggest that the tracheary elements of some vesselless angiosperms differ in width and hydraulic efficiency from conifer tracheids.
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Jawaray, Wilfridus Balla, Erfy Melany Lalupan, Anita Tamu Ina, and Agus Kusumanegara. "KEANEKARAGAMAN TUMBUHAN ANGIOSPERMAE DI KAWASAN TAMAN NASIONAL MATALAWA KABUPATEN SUMBA TIMUR." Jurnal Biosilampari : Jurnal Biologi 5, no. 2 (June 1, 2023): 169–77. http://dx.doi.org/10.31540/biosilampari.v5i2.1708.
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The highest plant diversity in the tropical rainforest area in Matalawa National Park is the Angiospermae plant. There are still many people in Praingkareha Village who are not familiar with Angiospermae plants or closed seed plants. This study aims to describe the diversity index of Angiosperm plants found in the Laputi Forest block, Matalawa National Park. This research was limited to the Laputi Forest block, so it did not cover the entire forest in Praingkareha Village, Matalawa National Park, East Sumba Regency. This study used a double plot method with a purposive sampling technique. The results showed that there were 30 species of Angiosperms from 17 families with a total of 499 individuals. The diversity of Angiosperm plants in the Laputi Forest block of the Matalawa National Park area is moderate with (Ĥ)=2.90.
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Sen, S. P., and D. G. Dutta Roy. "DNA homology as a tool for determination of divergence of phanerogamic taxa." Journal of Palaeosciences 41 (December 31, 1992): 159–66. http://dx.doi.org/10.54991/jop.1992.1117.
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The utility of DNA homology as tool for determination of divergence of phanerogamic taxa is discussed. DNA-DNA hybridization values of living gymnosperms and members of primitive angiospermic families indicate highest homology between Gnetum and Magnoliaceae, supporting the gnetalean origin of angiosperms. Conifers like Thuja occidentalis show no less homology with primitive angiosperm families than do the cycads. The living monocots and gymnosperms have diverged even farther. The primitive dicotyledonous families revealed fairly high homology among themselves but the other more derived families have diverged appreciably. The DNA homology among the primitive dicots and monocots varied between 45 and 60 per cent. With respect to the more advanced families, the homology values decreased. Families at moderate levels of evolutionary advancement exhibit intermediate values when compared. The two major groups of angiosperms seem to have evolved along parallel lines from a common stock in the remote past.
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Ishibashi, Kota, Ian Small, and Toshiharu Shikanai. "Evolutionary Model of Plastidial RNA Editing in Angiosperms Presumed from Genome-Wide Analysis of Amborella trichopoda." Plant and Cell Physiology 60, no. 10 (May 31, 2019): 2141–51. http://dx.doi.org/10.1093/pcp/pcz111.
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Abstract Amborella trichopoda is placed close to the base of the angiosperm lineage (basal angiosperm). By genome-wide RNA sequencing, we identified 184C-to-U RNA editing sites in the plastid genome of Amborella. This number is much higher than that observed in other angiosperms including maize (44 sites), rice (39 sites) and grape (115 sites). Despite the high frequency of RNA editing, the biased distribution of RNA editing sites in the genome, target codon preference and nucleotide preference adjacent to the edited cytidine are similar to that in other angiosperms, suggesting a common editing machinery. Consistent with this idea, the Amborella nuclear genome encodes 2–3 times more of the E- and DYW-subclass members of pentatricopeptide repeat proteins responsible for RNA editing site recognition in plant organelles. Among 165 editing sites in plastid protein coding sequences in Amborella, 100 sites were conserved at least in one out of 38 species selected to represent key branching points of the angiosperm phylogenetic tree. We assume these 100 sites represent at least a subset of the sites in the plastid editotype of ancestral angiosperms. We then mapped the loss and gain of editing sites on the phylogenetic tree of angiosperms. Our results support the idea that the evolution of angiosperms has led to the loss of RNA editing sites in plastids.
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Wang, Xin. "Origin of Angiosperms: Problems, Challenges, and Solutions." Life 13, no. 10 (October 9, 2023): 2029. http://dx.doi.org/10.3390/life13102029.
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Angiosperms are frequently assumed to constitute a monophyletic group. Therefore, the origin of angiosperms is a key question in systematic botany since the answer to this question is hinged with many questions concerned with angiosperm evolution. Previously, the lack of fossil evidence undermines the robustness of related hypotheses, and explains the instability of the systematics of angiosperms in the past century. With increasing evidence of early angiosperms, the origin and early evolution of angiosperms become approachable targets. However, reaching a strict consensus is still a mission impossible now: there are too many issues open to debate. A good sign in research is that palaeobotanists started addressing the issue of criterion identifying angiosperms, this would bring order in studies of early angiosperms. Several flaws in fundamental concepts inflicting botany require efforts to elucidate and remedy. The author here opens a discussion on these problems, hoping that more botanists will join to discuss and clarify previously blurry concepts and place a solid foundation for future development in botany.
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Liu, Zhong-Jian, Ye-Mao Hou, and Xin Wang. "Zhangwuia: an enigmatic organ with a bennettitalean appearance and enclosed ovules." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 108, no. 4 (December 2017): 419–28. http://dx.doi.org/10.1017/s1755691018000257.
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ABSTRACTThe feature distinguishing typical angiosperms from gymnosperms is that their ovules are enclosed before pollination. Bennettitales were formerly related to angiosperms because of the flower-like organisation of the former's reproductive organs. There is little information on how the naked ovules of Bennettitales became enclosed in angiosperms because fossil evidence for such a transition, if it exists, has not been described. Here, we report a reproductive organ, Zhangwuia gen. nov., from the Middle Jurassic of Inner Mongolia, China. Like many Bennettitales, the arrangement of the foliar parts around the female part in Zhangwuia demonstrates a resemblance to typical angiosperm flowers. It is noteworthy that the ovule is secluded from the exterior space in Zhangwuia, therefore implying the existence of angio-ovuly. Although Bennettitales have been related to angiosperms for more than a hundred years, their way of ovule-enclosing was not previously revealed. The discovery of Zhangwuia prompts a rethinking of the relationship between Bennettitales and angiosperms, as well as of the origin of angiosperms.
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McKenna, Duane D., Andrea S. Sequeira, Adriana E. Marvaldi, and Brian D. Farrell. "Temporal lags and overlap in the diversification of weevils and flowering plants." Proceedings of the National Academy of Sciences 106, no. 17 (April 13, 2009): 7083–88. http://dx.doi.org/10.1073/pnas.0810618106.
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The extraordinary diversity of herbivorous beetles is usually attributed to coevolution with angiosperms. However, the degree and nature of contemporaneity in beetle and angiosperm diversification remain unclear. Here we present a large-scale molecular phylogeny for weevils (herbivorous beetles in the superfamily Curculionoidea), one of the most diverse lineages of insects, based on ≈8 kilobases of DNA sequence data from a worldwide sample including all families and subfamilies. Estimated divergence times derived from the combined molecular and fossil data indicate diversification into most families occurred on gymnosperms in the Jurassic, beginning ≈166 Ma. Subsequent colonization of early crown-group angiosperms occurred during the Early Cretaceous, but this alone evidently did not lead to an immediate and major diversification event in weevils. Comparative trends in weevil diversification and angiosperm dominance reveal that massive diversification began in the mid-Cretaceous (ca.112.0 to 93.5 Ma), when angiosperms first rose to widespread floristic dominance. These and other evidence suggest a deep and complex history of coevolution between weevils and angiosperms, including codiversification, resource tracking, and sequential evolution.
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Brodribb, T. J., N. M. Holbrook, and R. S. Hill. "Seedling growth in conifers and angiosperms: impacts of contrasting xylem structure." Australian Journal of Botany 53, no. 8 (2005): 749. http://dx.doi.org/10.1071/bt05049.
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Competitive interaction between conifers and angiosperms has moulded the structure of global vegetation since the Cretaceous. Angiosperms appear to enjoy their greatest advantage in the lowland tropics, an advantage often attributed to the presence of vessels in their xylem tissue. By monitoring the seedling growth of three members of the pan-tropical conifer family Podocarpaceae and three tropical angiosperm tree species, our aim was to determine whether these conifer and angiosperm seedlings showed distinct patterns of growth and light adaptation that might be attributed to the presence/absence of vessels. Angiosperm seedlings were consistently more efficient in terms of leaf area carried per unit stem investment, as well as more responsive to light climate than the conifer seedlings. Apparently linked to this were larger growth rate, stem hydraulic conductivity and stomatal conductance in the angiosperm sample. Stem hydraulic conductivity and maximum stomatal conductance were highly correlated among species and light treatments explaining the association between highly conductive vessel-bearing wood and high rates of gas exchange. We conclude that xylem vessels contribute to higher rates of gas exchange and more efficient production of leaf area in our sample angiosperms than in conifers. However, this advantage is limited by shade.
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Bao, Tong, Bo Wang, Jianguo Li, and David Dilcher. "Pollination of Cretaceous flowers." Proceedings of the National Academy of Sciences 116, no. 49 (November 11, 2019): 24707–11. http://dx.doi.org/10.1073/pnas.1916186116.
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Insect pollination of flowering plants (angiosperms) is responsible for the majority of the world’s flowering plant diversity and is key to the Cretaceous radiation of angiosperms. Although both insects and angiosperms were common by the mid-Cretaceous, direct fossil evidence of insect pollination is lacking. Direct evidence of Cretaceous insect pollination is associated with insect-gymnosperm pollination. Here, we report a specialized beetle-angiosperm pollination mode from mid-Cretaceous Burmese amber (99 mega-annum [Ma]) in which a tumbling flower beetle (Mordellidae), Angimordella burmitina gen. et sp. nov., has many tricolpate pollen grains attached. A. burmitina exhibits several specialized body structures for flower-visiting behavior including its body shape and pollen-feeding mouthparts revealed by X-ray microcomputed tomography (micro-CT). The tricolpate pollen in the amber belongs to the eudicots that comprise the majority of extant angiosperm species. These pollen grains exhibit zoophilous pollination attributes including their ornamentation, size, and clumping characteristics. Tricolpate pollen grains attached to the beetle’s hairs are revealed by confocal laser scanning microscopy, which is a powerful tool for investigating pollen in amber. Our findings provide direct evidence of insect pollination of Cretaceous angiosperms, extending the range insect-angiosperm pollination association by at least 50 million years. Our results support the hypothesis that specialized insect pollination modes were present in eudicots 99 million years ago.
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Vasanthy, G., B. S. Venkatachala, and S. A. J. Pocock. "The evolution of angiospermid pollen characteristics: conjectures and queries." Journal of Palaeosciences 38 (December 31, 1989): 131–46. http://dx.doi.org/10.54991/jop.1989.1647.
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The origin and evolution of different exine layers of palynofossils is analysed in the light of accumulating ultrastructural data. Semi-diagramatic illustrations based on the published TEM results of various exine types representing a cross section of extinct and extant plant groups are given for easy reference and comprehension. Some of the important palynological questions and issues discussed in the present work are imprecise use to describe the infra-tectum of pollen, of the flexible term "granular" that often leads to erroneous derivations and conclusions; ontogenetic differences between the apparently similar complexly alveolate columellate sexine types of gymnosperms and angiosperms respectively; independent evolution of columellar complexity in unrelated taxa: role of ubiquitous white lines in the exines of extinct and extant spores and pollen and adaptive rather than phylogenetic significance of sacci in progymnosperms, gymnosperms and angiosperms. Despite recognition of angiospermid pollen characteristics especially in tectally reticulate and columellate pollen of Triassic (Cornet, 1979, 1985, 1989; Pocock & Vasanthy, 1988; Pocock, Vasanthy & Venkatachala. 1988) the pre-Cretaceous origin of angiosperm still remains an open question.
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Martín Bravo, Santiago, José Manuel Herrera Rodríguez, and Iñigo Pulgar Sañudo. "Notas corológicas para la provincia de Sevilla." Acta Botanica Malacitana 44 (September 26, 2019): 103–8. http://dx.doi.org/10.24310/abm.v44i0.5273.
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Biffin, Ed, Timothy J. Brodribb, Robert S. Hill, Philip Thomas, and Andrew J. Lowe. "Leaf evolution in Southern Hemisphere conifers tracks the angiosperm ecological radiation." Proceedings of the Royal Society B: Biological Sciences 279, no. 1727 (June 8, 2011): 341–48. http://dx.doi.org/10.1098/rspb.2011.0559.
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The angiosperm radiation has been linked to sharp declines in gymnosperm diversity and the virtual elimination of conifers from the tropics. The conifer family Podocarpaceae stands as an exception with highest species diversity in wet equatorial forests. It has been hypothesized that efficient light harvesting by the highly flattened leaves of several podocarp genera facilitates persistence with canopy-forming angiosperms, and the angiosperm ecological radiation may have preferentially favoured the diversification of these lineages. To test these ideas, we develop a molecular phylogeny for Podocarpaceae using Bayesian-relaxed clock methods incorporating fossil time constraints. We find several independent origins of flattened foliage types, and that these lineages have diversified predominantly through the Cenozoic and therefore among canopy-forming angiosperms. The onset of sustained foliage flattening podocarp diversification is coincident with a declining diversification rate of scale/needle-leaved lineages and also with ecological and climatic transformations linked to angiosperm foliar evolution. We demonstrate that climatic range evolution is contingent on the underlying state for leaf morphology. Taken together, our findings imply that as angiosperms came to dominate most terrestrial ecosystems, competitive interactions at the foliar level have profoundly shaped podocarp geography and as a consequence, rates of lineage diversification.
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Gaff, Donald F., and Melvin Oliver. "The evolution of desiccation tolerance in angiosperm plants: a rare yet common phenomenon." Functional Plant Biology 40, no. 4 (2013): 315. http://dx.doi.org/10.1071/fp12321.
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In a minute proportion of angiosperm species, rehydrating foliage can revive from airdryness or even from equilibration with air of ~0% RH. Such desiccation tolerance is known from vegetative cells of some species of algae and of major groups close to the evolutionary path of the angiosperms. It is also found in the reproductive structures of some algae, moss spores and probably the aerial spores of other terrestrial cryptogamic taxa. The occurrence of desiccation tolerance in the seed plants is overwhelmingly in the aerial reproductive structures; the pollen and seed embryos. Spatially and temporally, pollen and embryos are close ontogenetic derivatives of the angiosperm microspores and megaspores respectively. This suggests that the desiccation tolerance of pollen and embryos derives from the desiccation tolerance of the spores of antecedent taxa and that the basic pollen/embryo mechanism of desiccation tolerance has eventually become expressed also in the vegetative tissue of certain angiosperm species whose drought avoidance is inadequate in micro-habitats that suffer extremely xeric episodes. The protective compounds and processes that contribute to desiccation tolerance in angiosperms are found in the modern groups related to the evolutionary path leading to the angiosperms and are also present in the algae and in the cyanobacteria. The mechanism of desiccation tolerance in the angiosperms thus appears to have its origins in algal ancestors and possibly in the endosymbiotic cyanobacteria-related progenitor of chloroplasts and the bacteria-related progenitor of mitochondria. The mechanism may involve the regulation and timing of the accumulation of protective compounds and of other contributing substances and processes.
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Qi, Yang, Hongyan Liu, Chongyang Xu, Jingyu Dai, and Biao Han. "Dry Climate Filters Gymnosperms but Not Angiosperms through Seed Mass." Diversity 15, no. 3 (March 10, 2023): 401. http://dx.doi.org/10.3390/d15030401.
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In the context of climate change in recent years, the fate of woody plant seed has an important impact on forest regeneration. Seed mass is an important reproductive strategy of plants. There are huge differences between gymnosperms (mainly conifers) and angiosperms (flowering plants) in terms of reproduction and hydraulic strategies; however, little is known about changes in seed mass along climate aridity gradients between taxonomical groups such as gymnosperms and angiosperms, which limit our understanding on the fate of woody plants under warming-induced climate drying. We collected seed mass data from a total of 2575 woody plant individuals, including 145 species of gymnosperms and 1487 species of angiosperms, across different climatic zones in China. We mapped the distribution pattern of gymnosperm and angiosperm seed mass in China, with angiosperms being maximal near the 400 mm iso-precipitation line. Our phylogenetic analysis results show that seed mass exhibited significant phylogenic signals (p < 0.001) and was also strongly influenced by functional traits (growth type, fruit type, and dispersal mode). The results of linear regression and hierarchical partitioning analysis showed a stronger correlation between gymnosperm seed mass and environmental factors, and a higher independent aridity index effect on gymnosperm seed mass than angiosperm seed mass. The different patterns of seed mass along a climate aridity gradient between gymnosperms and angiosperms may point to different future fates for these two taxonomic groups, while the higher sensitivity of gymnosperm seed mass to environmental conditions may reduce their reproductive rate under the background of climate warming and drying.
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Herman, A. B., V. V. Kostyleva, P. A. Nikolskii, A. E. Basilyan, and A. E. Kotel’nikov. "New data on the late cretaceous flora of the New Siberia island, New Siberian Islands." Стратиграфия 27, no. 3 (April 22, 2019): 53–69. http://dx.doi.org/10.31857/s0869-592x27353-69.
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New plant fossils collected in 2016 from the Derevyannye Gory Formation on the New Siberia Island are studied. Thirty species of fossil plants are identified and illustrated. They belong to liverworts, ferns, ginkgoaleans, conifers and angiosperms. Sixteen of them have not beed found in the New Siberia Flora before. A new angiosperm species Dalembia (?) gracilis Herman is described. The New Siberia Flora is characterised by a moderately high taxonomic diversity, predominance of conifers and angiosperms with large-leafed platanoids and trochodendroids being the most abundant among angiosperms, by predominance of dentate-margined angiosperms and rarity of plants with entire-margined leaves, and by absence of cycadaleans and bennettitaleans. The flora existed during the Turonian–Coniacian time interval and most probably should be dated as Turonian. Plants of the New Siberia Flora experienced a warm-temperate humid climate with warm summers, mild frost-free winters and insignificant seasonality in precipitation.
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Friis, Else Marie, Peter R. Crane, and Kaj Raunsgaard Pedersen. "The Early Cretaceous Mesofossil Flora of Torres Vedras (Ne of Forte Da Forca), Portugal: A Palaeofloristic Analysis of an Early Angiosperm Community." Fossil Imprint 75, no. 2 (November 1, 2019): 153–257. http://dx.doi.org/10.2478/if-2019-0013.
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Abstract An Early Cretaceous mesofossil flora is described from the lower part of the Almargem Formation (late Barremian-early Aptian) from Torres Vedras (NE of Forte da Forca), Portugal. The flora is the oldest mesofossil flora containing angiosperm remains to be described in detail based on well-preserved flower, fruit and seed remains. In addition to angiosperms, the mesofossil flora also includes megaspores, sporangia and tiny leaves of spore-bearing plants. There are also twigs, cone fragments and seeds of conifers and seeds assigned to the BEG group. In total about 100 species have been distinguished. Most abundant in terms of plant fragments identified, are spore-bearing plants and conifers. Although only about 18 % of the specimens can be attributed to angiosperms, angiosperm diversity is unexpected high considering the age of the flora. Angiosperms account for about 62 % of all species recognized. Angiosperm diversity is mainly at the level of ANA-grade angiosperms, eumagnoliids and in a few cases early diverging lineages of monocots. Eudicots are subordinate. Twenty new genera and 28 new species of angiosperms are established (Anaspermum operculatum gen. et sp. nov., Appofructus nudus gen. et sp. nov., Appomattoxia minuta sp. nov., Burgeria striata gen. et sp. nov., Canrightia elongata sp. nov., Choffaticarpus compactus gen. et sp. nov., Dejaxia brevicolpites gen. et sp. nov., Dinisia portugallica gen. et sp. nov., Eckhartia brevicolumella gen. et sp. nov., Eckhartia longicolumella sp. nov., Eckhartia intermedia sp. nov., Eckhartianthus lusitanicus gen. et sp. nov., Eckhartiopsis parva gen. et sp. nov., Gastonispermum antiquum sp. nov., Goczania rugosa gen. et sp. nov., Goczania inaequalis sp. nov., Goczania punctata sp. nov., Ibrahimia verminculata gen. et sp. nov., Juhaszia portugallica gen. et sp. nov., Kempia longicolpites gen. et sp. nov., Kvacekispermum costatum sp. nov., Mcdougallia irregularis gen. et sp. nov., Nicholsia brevicolpites gen. et sp. nov., Piercipollis simplex gen. et sp. nov., Reyanthus lusitanicus gen. et sp. nov., Samylinaea punctata gen. et sp. nov., Teebacia hughesii gen. et sp. nov., Vedresia elliptica gen. et sp. nov.). Comparison with results of a palynological study from the same horizon that yielded the mesofossil flora shows a marked underestimation of angiosperm diversity in the palynoflora, a pattern that has also been recognized elsewhere.
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Bechtel, Achim, and Doris Groß. "Insights into floral and climatic changes from biomarker and isotopic composition of land plant organic matter – A review." Review of the Bulgarian Geological Society 85, no. 1 (July 2024): 67–70. http://dx.doi.org/10.52215/rev.bgs.2024.85.1.67.
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Biomarkers and isotopic composition of coal and plant tissue enable insights into floral assemblage and paleoenvironment. Abundance, distribution, and d13C values of leaf wax lipids (i.e. n-alkanes) differ between angiosperm and gymnosperm plants. Terpenoid hydrocarbons are used to assess the contributions of gymnosperms versus angiosperms. The influence of varying contributions of angiosperms and gymnosperms on d13C of coal can be overcome by the analyses of fossil wood remains for their isotopic composition. Angiosperms and gymnosperms show similar H-isotope fractionation between n-alkanes and water. Diterpenoids yield lower d2H values compared to angiosperm-derived triterpenoids, due to different biosynthetic pathways. Differences in mean annual precipitation affect d13C of bulk leaf organic matter. Co-variations in d13C and d2H of lipids reflect changes in water availability to the plants. Temperature variations, based on branched glycerol dialkyl glycerol tetraethers (brGDGTs), and d2H values of n-C29 alkane from Lake Van sediments reveal warm-humid climate during interglacials and cooler and drier climate during glacials. Based on the methylation of brGDGTs, a calibrated paleothermometer is available for peats and lignites.
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Nyman, Tommi, Renske E. Onstein, Daniele Silvestro, Saskia Wutke, Andreas Taeger, Niklas Wahlberg, Stephan M. Blank, and Tobias Malm. "The early wasp plucks the flower: disparate extant diversity of sawfly superfamilies (Hymenoptera: ‘Symphyta’) may reflect asynchronous switching to angiosperm hosts." Biological Journal of the Linnean Society 128, no. 1 (July 1, 2019): 1–19. http://dx.doi.org/10.1093/biolinnean/blz071.
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AbstractThe insect order Hymenoptera originated during the Permian nearly 300 Mya. Ancestrally herbivorous hymenopteran lineages today make up the paraphyletic suborder ‘Symphyta’, which encompasses c. 8200 species with very diverse host-plant associations. We use phylogeny-based statistical analyses to explore the drivers of diversity dynamics within the ‘Symphyta’, with a particular focus on the hypothesis that diversification of herbivorous insects has been driven by the explosive radiation of angiosperms during and after the Cretaceous. Our ancestral-state estimates reveal that the first symphytans fed on gymnosperms, and that shifts onto angiosperms and pteridophytes – and back – have occurred at different time intervals in different groups. Trait-dependent analyses indicate that average net diversification rates do not differ between symphytan lineages feeding on angiosperms, gymnosperms or pteridophytes, but trait-independent models show that the highest diversification rates are found in a few angiosperm-feeding lineages that may have been favoured by the radiations of their host taxa during the Cenozoic. Intriguingly, lineages-through-time plots show signs of an early Cretaceous mass extinction, with a recovery starting first in angiosperm-associated clades. Hence, the oft-invoked assumption of herbivore diversification driven by the rise of flowering plants may overlook a Cretaceous global turnover in insect herbivore communities during the rapid displacement of gymnosperm- and pteridophyte-dominated floras by angiosperms.
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Nurrahma, Aditiya, Ismanto ., and Taufikurrahman Nasution. "KEANEKARAGAMAN EPIFIT BERPEMBULUH PADA BATANG POHON INANG ANGIOSPERMAE DAN GYMNOSPERMAE DI KEBUN RAYA CIBODAS." EKOLOGIA 22, no. 2 (October 31, 2022): 75–82. http://dx.doi.org/10.33751/ekologia.v22i2.5789.
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Epiphytes are types of plants that attach and grow on other plants to obtain sunlight, water, air, and minerals for their growth. The aim of this study are knowing the diversity of vascular epiphytes on the host trunks of Angiosperms and Gymnosperms, knowing the differences in vascular epiphytic communities on the host trunks of Angiosperms and Gymnosperms and to determine factors causing vascular epiphytes communities on the host trunk is used in this research. Sampling plot is located on the host tree's trunk to facilitate the calculation of vascular epiphytes; a simple plot measuring 2 m x 0,5 m was made facing east and west. Determination of the number of tree sampling is done based on the Area Species Curve. The results of this study indicate that the vascular epiphyte diversity on trunks of Gymnospermae is higher than Angiospermae, meanwhile that Shannon Wiener diversity index of vascular epiphytes on Angiosperms and Gymnosperms host trunks being moderate category. Jaccard Similarity index was 0.44 and indicated the different of epiphytes community between Angiospermae and Gymnospermae tree host. The dominant species based on Important value index in Angiosperms are Davallia hymenophylloides (35,05%), Goniophlebium subauriculatum (20,92%), and Dendrobium mutabile (20,07) while ini Gymnosperme are Davallia hymenophylloides (41,36%), Goniophlebium subauriculatum (15,94%), and Peperomia tetraphylla (15,55%). In Angiospermae, the factors that influence the diversity of vascular epiphyte species are roughness and thickness, while in Gymnosperms the influential factors are roughness and diameter.
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Pouteau, Robin, Santiago Trueba, and Sandrine Isnard. "Retracing the contours of the early angiosperm environmental niche." Annals of Botany 125, no. 1 (August 12, 2019): 49–57. http://dx.doi.org/10.1093/aob/mcz131.
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Abstract Background and Aims Our aim was to understand the environmental conditions of the emergence and radiation of early angiosperms. Such a question has long remained controversial because various approaches applied in the past have drawn conflicting images of early angiosperm ecology. Methods We provided a new perspective on the question by using support vector machines to model the environmental niche of 51 species belonging to ten genera of extant lineages that diverged early during angiosperm evolution (basal angiosperms). Then, we analysed the resulting pattern of niche overlap and determined whether this pattern deviates from what would be expected on the basis of a null model or whether it might mirror a legacy of a common primitive niche based on a phylogenetic reconstruction. Key Results The niche of three-quarters of the species and all genera converged towards tropical montane cloud forests (TMCFs). The latitudinal pattern of basal angiosperm richness indeed culminated in the tropics, and the elevational pattern revealed a humpback curve peaking between 2000 m and 3500 m when accounting for the effect of area. At first glance, this diversity pattern does not significantly differ from null predictions. However, we revealed a tendency for the basal-most taxa to occur in TMCFs so that phylogenetic reconstructions indicated that the niche of the common ancestor of the sampled basal angiosperms had a probability of 0.85–0.93 to overlap with TMCFs. Conclusions Our new approach indicates that the environmental convergence of extant basal angiosperms towards TMCFs would reflect a legacy of an ancestral niche from which the least basal taxa would have diverged following a random pattern under geometric constraints.
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Kinlaw, C. S., D. E. Harry, and R. R. Sederoff. "Isolation and characterization of alcohol dehydrogenase cDNAs from Pinusradiata." Canadian Journal of Forest Research 20, no. 9 (September 1, 1990): 1343–50. http://dx.doi.org/10.1139/x90-178.
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Three alcohol dehydrogenase (ADH) cDNAs were isolated from Pinusradiata. Two of the cDNAs appear to correspond to alleles of one ADH locus, and the third cDNA appears to correspond to a second ADH locus. Nucleotide and amino acid sequences of the coding region of ADH genes from the following species were compared: Pinusradiata, Zeamays, Hordeumvulgare, Triticumaestivum, Oryza sativa, Pisumsativum, and Arabidopsisthaliana. A phylogenetic tree was constructed of coding sequences of pine and angiosperm ADH genes. This tree shows three plant ADH clusters: monocot, dicot, and pine. The distance between pine and the two angiosperms is only slightly greater than the distance between either angiosperm, supporting the fossil evidence that suggests that monocots and dicots diverged from each other shortly after angiosperms diverged from gymnosperms. The structure of pine ADH genes was investigated by Southern blot analysis. The restriction fragment pattern of ADH genes from pines is more complex than the pattern from angiosperm genes, suggesting that pine ADH genes are either larger or more numerous than their angiosperm counterparts.
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Ruban, Dmitry. "Mesozoic mass extinctions and angiosperm radiation: does the molecular clock tell something new?" Geologos 18, no. 1 (March 1, 2012): 37–42. http://dx.doi.org/10.2478/v10118-012-0003-3.
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Mesozoic mass extinctions and angiosperm radiation: does the molecular clock tell something new?Angiosperms evolved rapidly in the late Mesozoic. Data from the genetic-based approach called ‘molecular clock’ permit an evaluation of the radiation of flowering plants through geological time and of the possible influences of Mesozoic mass extinctions. A total of 261 divergence ages of angiosperm families are considered. The radiation of flowering plants peaked in the Albian, early Campanian, and Maastrichtian. From the three late Mesozoic mass extinctions (Jurassic/Cretaceous, Cenomanian/Turonian, and Cretaceous/Palaeogene), only the Cretaceous/Palaeogene event coincided with a significant, abrupt, and long-term decline in angiosperm radiation. If their link will be further proven, this means that global-scale environmental perturbation precluded from many innovations in the development of plants. This decline was, however, not unprecedented in the history of the angiosperms. The implication of data from the molecular clock for evolutionary reconstructions is limited, primarily because this approach deals with only extant lineages.
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Mehrotra, R. C. "Antiquity and migratory paths of angiosperms in India." Journal of Palaeosciences 57, no. (1-3) (December 31, 2008): 217–20. http://dx.doi.org/10.54991/jop.2008.237.
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In India the earliest angiospermous plants are known in the form of pollen/fruit or ?flower from the Lower Cretaceous (Aptian) of Rajmahal flora. Unfortunately, the Lower and Middle Cretaceous records of angiosperms from India are very poor as compared to those in other continents. The definite records of angiosperms started appearing from the Lameta flora considered as Maastrichtian in age. During the Upper Maastrichtian-Danian they became the most dominant element of the flora. An influx of Southeast Asian elements could only be noticed in the beginning of the Neogene. During upheaval of the Himalayas, temperate angiosperms which were growing luxuriantly in the nearby areas of Tibet and Southwest China, invaded the Himalayan part of India under the prevailing favourable conditions.
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Santos, Artai A., and Xin Wang. "Pre-Carpels from the Middle Triassic of Spain." Plants 11, no. 21 (October 25, 2022): 2833. http://dx.doi.org/10.3390/plants11212833.
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In stark contrast to the multitude of hypotheses on carpel evolution, there is little fossil evidence testing these hypotheses. The recent discovery of angiosperms from the Early Jurassic makes the search for precursors of angiosperm carpels in the Triassic more promising. Our light microscopic and SEM observations on Combina gen. nov., a cone-like organ from the Middle Triassic of Spain, indicate that its lateral unit includes an axillary anatropous ovule and a subtending bract, and the latter almost fully encloses the former. Such an observation not only favors one of the theoretical predictions but also makes some Mesozoic gymnosperms (especially conifers and Combina) comparable to some angiosperms. Combina gen. nov. appears to be an important chimeric fossil plant that may complete the evidence chain of the origin of carpels in geological history, partially narrowing the gap between angiosperms and gymnosperms.
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Adams, Keith L., Monica Rosenblueth, Yin-Long Qiu, and Jeffrey D. Palmer. "Multiple Losses and Transfers to the Nucleus of Two Mitochondrial Succinate Dehydrogenase Genes During Angiosperm Evolution." Genetics 158, no. 3 (July 1, 2001): 1289–300. http://dx.doi.org/10.1093/genetics/158.3.1289.
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Abstract Unlike in animals, the functional transfer of mitochondrial genes to the nucleus is an ongoing process in plants. All but one of the previously reported transfers in angiosperms involve ribosomal protein genes. Here we report frequent transfer of two respiratory genes, sdh3 and sdh4 (encoding subunits 3 and 4 of succinate dehydrogenase), and we also show that these genes are present and expressed in the mitochondria of diverse angiosperms. Southern hybridization surveys reveal that sdh3 and sdh4 have been lost from the mitochondrion about 40 and 19 times, respectively, among the 280 angiosperm genera examined. Transferred, functional copies of sdh3 and sdh4 were characterized from the nucleus in four and three angiosperm families, respectively. The mitochondrial targeting presequences of two sdh3 genes are derived from preexisting genes for anciently transferred mitochondrial proteins. On the basis of the unique presequences of the nuclear genes and the recent mitochondrial gene losses, we infer that each of the seven nuclear sdh3 and sdh4 genes was derived from a separate transfer to the nucleus. These results strengthen the hypothesis that angiosperms are experiencing a recent evolutionary surge of mitochondrial gene transfer to the nucleus and reveal that this surge includes certain respiratory genes in addition to ribosomal protein genes.
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Roodt, Danielle, Zhen Li, Yves Van de Peer, and Eshchar Mizrachi. "Loss of Wood Formation Genes in Monocot Genomes." Genome Biology and Evolution 11, no. 7 (June 7, 2019): 1986–96. http://dx.doi.org/10.1093/gbe/evz115.
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Abstract Woodiness (secondary xylem derived from vascular cambium) has been gained and lost multiple times in the angiosperms, but has been lost ancestrally in all monocots. Here, we investigate the conservation of genes involved in xylogenesis in fully sequenced angiosperm genomes, hypothesizing that monocots have lost some essential orthologs involved in this process. We analyzed the conservation of genes preferentially expressed in the developing secondary xylem of two eudicot trees in the sequenced genomes of 26 eudicot and seven monocot species, and the early diverging angiosperm Amborella trichopoda. We also reconstructed a regulatory model of early vascular cambial cell identity and differentiation and investigated the conservation of orthologs across the angiosperms. Additionally, we analyzed the genome of the aquatic seagrass Zostera marina for additional losses of genes otherwise essential to, especially, secondary cell wall formation. Despite almost complete conservation of orthology within the early cambial differentiation gene network, we show a clear pattern of loss of genes preferentially expressed in secondary xylem in the monocots that are highly conserved across eudicot species. Our study provides candidate genes that may have led to the loss of vascular cambium in the monocots, and, by comparing terrestrial angiosperms to an aquatic monocot, highlights genes essential to vasculature on land.
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Dettmann, M. E. "Structure and floristics of Cretaceous vegetation of southern Gondwana: implications for angiosperm biogeography." Journal of Palaeosciences 41 (December 31, 1992): 224–33. http://dx.doi.org/10.54991/jop.1992.1125.
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A review of palaeobotanical/palynological data reveals that the vegetation of southern Gondwana was regionalised throughout the Cretaceous. Open forests of high productivity occurred in high southern latitudes whereas woodlands, heathlands and closed forests vegetated mid-latitudinal areas. Angiosperms first entered the region during Barremian-Aptian times from source areas in northern Gondwana. Early immigrants to the Australian-Antarctic assembly were of magnoliid stock, and migration routes involved southern South America. Early angiosperms in India also included non-magnoliid taxa which may have utilised an African/Madagascar corridor. Non-magnoliid angiosperms spread to the Austro-Antarctic landmass during the Albian, some 5-10 Ma after India was isolated from the southern Gondwanan assembly. For the remainder of the Cretaceous southern South America and the Antarctic Peninsula served as an exchange corridor for angiosperms between northern and southern Gondwana. This area was also the cradle of Nothofagus, whereas diametrically opposed land adjacent to the embryonic Southern Ocean was a differentiation centre for the Proteaceae. Angiosperm migration was step wise, and regulated by changing environmental circumstances associated with tectonic/volcanic activity and opening and enlargement of the southern oceans.
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Chambers, Patricia A., and Jacob Kaiff. "Depth Distribution and Biomass of Submersed Aquatic Macrophyte Communities in Relation to Secchi Depth." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 4 (April 1, 1985): 701–9. http://dx.doi.org/10.1139/f85-090.
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Using original data from eight lakes in southern Quebec and literature values from other fakes throughout the world, regression models were developed that allow prediction of the maximum depth of macrophyte colonization (zc) for angiosperms ((zc)0.5 = 1.33 log (D) + 1.40), bryophytes (zc)−0.5 = −0.48 log (D) + 0.81), and charophytes (log (zc) = 0.87 log (D) + 0.31) and the depth of maximum angiosperm biomass (zb)(zb0.5 = 0.54 log (D) + 1.15) from mean summer Secchi depth (D). Irradiance over the growing season at the maximum depth of colonization was about 1800 J/cm2 (1 cal/cm2 = 0.239 J/cm2) for angiosperms and bryophytes and 1200 J/cm2 for charophytes. These values represent, on average, 21 and 11% of the photo-synthetically available radiation incident on the water surface. Changes in maximum angiosperm biomass were, however, not correlated with Secchi depth. This suggests that while the depth distribution of aquatic macrophyte communities is primarily controlled by irradiance, environmental parameters other than irradiance and nutrients are also important in determining maximum angiosperm biomass in individual lakes.
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Romero, Edgardo J., and Ricardo Palma. "Early angiosperm fossil leaves in Chubut Group, Cretaceous, Argentina." Paleontological Society Special Publications 6 (1992): 250. http://dx.doi.org/10.1017/s2475262200008108.
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The oldest angiosperm leaves from Patagonia were reported from Baquero Formation (Barremian-Aptian) in a mesofitic flora of more than one hundred gymnosperm and fern species. The next younger records are from the Chubut Group, a thick assemblage of pyroclastic sediments, with sand and conglomerate facies and frequent paleosols. In the Sierra de San Bernardo area sediments are mainly tufaceous and fluvial, deposited under an arid climate in shallow lakes and swamps of the alluvial plains. The sea was hundreds of kilometers to the West. Four Formations were described: Matasiete (Aptian), Castillo and Bajo Barreal (Senonian) and Laguna Palacios (Campanian-Maastrichtian). We explored in the Senonian Formations, and studied a few outcrops that can be sorted as:a) Monospecific, with only Onychiopsis sp., in palustral sediments. b) Strongly dominated by Eauisetum sp, and few remains of two dicot species with large, entire margined, low rank leaves, in palustral sediments. c) Strongly dominated by two species of angiosperms with small leaves, associated with remains of conifers in tufaceous beds deposited in the alluvial plain. d) Dominated by a few species of dicots, with medium size, entire margined leaves. Also with about 10 species of ferns, gymnosperms and lobate angiosperms. They are in alluvial plains sediments. e) More balanced associations, with several abundant species, including angiosperms with lobate and leaves. They are in fluvial sediments.Although angiosperm radiation and taphonomy undoubtedly accounts for differences of plant composition between outcrops, it seems apparent that the record of early angiosperms in Chubut Group is represented by remains of many different plant associations, with few species, adapted to different environments, that probably coexisted, and developed under an arid climate, far from the sea.
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Hochuli, Peter A., and Susanne Feist-Burkhardt. "A boreal early cradle of Angiosperms? Angiosperm-like pollen from the Middle Triassic of the Barents Sea (Norway)." Journal of Micropalaeontology 23, no. 2 (November 1, 2004): 97–104. http://dx.doi.org/10.1144/jm.23.2.97.
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Abstract. The origin of flowering plants is still a matter of dispute. Several lines of evidence suggest that their origin may go back to the Triassic. This paper reports on pollen grains with angiosperm-like morphologies from marine Middle Triassic sediments of the Boreal Realm (Norwegian Arctic, Barents Sea area). The morphology of these pollen grains is comparable to forms recorded from the Early Cretaceous, which are generally attributed to angiosperms. The new finds of angiosperm-like pollen are the earliest in the fossil record so far and show an astonishing high diversity. In contrast to other early records, they come from high palaeolatitudes with an inferred warm-temperate climate. The new finds suggest the presence of the first angiosperms during the Middle Triassic (242–227 Ma) or, alternatively, provide evidence for an as-yet unknown group of gymnosperms, possibly an extinct sister group of the flowering plants.
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Philippe, Marc, and Dmitri Gromyko. "The Putative Jurassic Angiosperm Wood Suevioxylon Zonatum Revisited." IAWA Journal 28, no. 1 (2007): 95–100. http://dx.doi.org/10.1163/22941932-90001622.
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As the phylogeny and evolution of angiosperms is being completely rewritten by molecular data, there is renewed interest in the earliest fossil record of the group. A putative Jurassic Angiosperm wood, Suevioxylon zonatum Kräusel is revisited. We reinvestigated the type material (specimen and five thin sections) with light microscopy and SEM. This reappraisal indicates that Suevioxylon zonatum is actually a poorly preserved softwood and not an angiosperm.
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Li, Haolun, Huali Chang, Jyrki Muona, Yanchen Zhao, and Dong Ren. "Subfamily Anischiinae (Coleoptera: Eucnemidae) in Early Cretaceous of Northeast China." Insects 12, no. 2 (January 26, 2021): 105. http://dx.doi.org/10.3390/insects12020105.
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Rheanischia new genus, type species Rheanischia brevicornis new species (Eucnemidae, Anischiinae) is described from the Lower Cretaceous of Liaoning, China. The presence of this species in early Cretaceous deposits provides new insight into the evolution of basal lignicolous Eucnemidae clades. Both Anischiinae and Palaeoxeninae species diversified in a world dominated by gymnosperms, before the main radiation of angiosperms. More than 95% of modern eucnemid larvae have a Palaeoxenus-type highly modified head structure, but contrary to the Palaeoxenus larva, they develop in angiosperm wood. Anischiinae utilize angiosperms as well, but their head capsule shows no such modifications. These facts prove that highly specialized morphological features do not offer definite proof of similar way of life in the distant past, nor should non-modified structures be taken as proof for another kind of substrate choice. Eucnemidae have invaded angiosperms with two quite different morphological adaptations. This fact may have implications for the evolution of all clicking elateroids.
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Golovneva, Lina, Eugenia Bugdaeva, Elena Volynets, Yuewu Sun, and Anastasia Zolina. "Angiosperm diversification in the Early Cretaceous of Primorye, Far East of Russia." Fossil Imprint 77, no. 2 (2021): 231–55. http://dx.doi.org/10.37520/fi.2021.017.
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The Partizansk and Razdolnaya coal basins of Primorye, Far East of Russia, contain diverse early angiosperm fossils (pollen, leaves, and fruits). In this paper, we revise the previous data on early angiosperms of this region and summarize the results of our latest research. Age of the plant-bearing deposits was clarified using isotopic U-Th-Pb LA-ICP-MS and U-Pb ID-TIMS methods. Age of the upper part of the Lipovtsy Formation is 118 ± 1.4 Ma, which corresponds to the late Aptian. The early Albian age (109 ± 1 Ma) is assigned to the upper part of the Frentsevka Formation. The diversification of angiosperms in the Early Cretaceous of Primorye region and their systematic affinity are analyzed. Early representatives of Laurales, Ranunculales, Platanaceae, and probable Cercidiphyllaceae are revealed. New combination Pandanites ahnertii (Krysht.) Golovn., comb. nov. is created, and new species Araliaephyllum vittenburgii Golovn. et Volynets, sp. nov. is described. Reconstructions of herbaceous angiosperms from autochthonous locality Bolshoy Kuvshin are proposed.
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Paterno, Gustavo Brant, Carina Lima Silveira, Johannes Kollmann, Mark Westoby, and Carlos Roberto Fonseca. "The maleness of larger angiosperm flowers." Proceedings of the National Academy of Sciences 117, no. 20 (May 4, 2020): 10921–26. http://dx.doi.org/10.1073/pnas.1910631117.
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Flower biomass varies widely across the angiosperms. Each plant species invests a given amount of biomass to construct its sex organs. A comparative understanding of how this limited resource is partitioned among primary (male and female structures) and secondary (petals and sepals) sexual organs on hermaphrodite species can shed light on general evolutionary processes behind flower evolution. Here, we use allometries relating different flower biomass components across species to test the existence of broad allocation patterns across the angiosperms. Based on a global dataset with flower biomass spanning five orders of magnitude, we show that heavier angiosperm flowers tend to be male-biased and invest strongly in petals to promote pollen export, while lighter flowers tend to be female-biased and invest more in sepals to insure their own seed set. This result demonstrates that larger flowers are not simple carbon copies of small ones, indicating that sexual selection via male–male competition is an important driver of flower biomass evolution and sex allocation strategies across angiosperms.
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Chen, Li-Jun, and Xin Wang. "A Flower Bud from the Lower Cretaceous of China." Biology 11, no. 11 (November 1, 2022): 1598. http://dx.doi.org/10.3390/biology11111598.
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Background: Although various angiosperms (including their flowers) have been reported from the Yixian Formation (Lower Cretaceous) of China, which is famous worldwide for its fossils of early angiosperms, no flower bud has hitherto been seen in the Early Cretaceous. Such a lack of examples hinders our understanding of the evolution of flowers. Methods: The specimen studied in the present paper was collected from an outcrop of the Yixian Formation (the Barremian-Aptian, Lower Cretaceous) of Dawangzhangzi in Lingyuan, Liaoning, China. The specimen was photographed using a Nikon D200 digital camera, its details were observed and photographed using a Nikon SMZ1500 stereomicroscope, and some of its details were observed using a Leo 1530 VP SEM. Results: We report a fossilized flower bud, Archaebuda lingyuanensis gen. et sp. nov, from the Yixian Formation of China. The debut of Archaebuda in the Yixian Formation provides first-hand material for debate on the early evolution of angiosperm flowers and underscores the great diversity of angiosperms in the Yixian Formation.
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Kordyum, Elizabeth L., and Sergei L. Mosyakin. "Endosperm of Angiosperms and Genomic Imprinting." Life 10, no. 7 (July 3, 2020): 104. http://dx.doi.org/10.3390/life10070104.
Full textAbstract:
Modern ideas about the role of epigenetic systems in the regulation of gene expression allow us to understand the mechanisms of vital activities in plants, such as genomic imprinting. It is important that genomic imprinting is known first and foremost for the endosperm, which not only provides an embryo with necessary nutrients, but also plays a special biological role in the formation of seeds and fruits. Available data on genomic imprinting in the endosperm have been obtained only for the triploid endosperm in model plants, which develops after double fertilization in a Polygonum-type embryo sac, the most common type among angiosperms. Here we provide a brief overview of a wide diversity of embryo sacs and endosperm types and ploidy levels, as well as their distribution in the angiosperm families, positioned according to the Angiosperm Phylogeny Group IV (APG IV) phylogenetic classification. Addition of the new, non-model taxa to study gene imprinting in seed development will extend our knowledge about the epigenetic mechanisms underlying angiosperm fertility.
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Zhang, Liangsheng, Fei Chen, Xingtan Zhang, Zhen Li, Yiyong Zhao, Rolf Lohaus, Xiaojun Chang, et al. "The water lily genome and the early evolution of flowering plants." Nature 577, no. 7788 (December 18, 2019): 79–84. http://dx.doi.org/10.1038/s41586-019-1852-5.
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AbstractWater lilies belong to the angiosperm order Nymphaeales. Amborellales, Nymphaeales and Austrobaileyales together form the so-called ANA-grade of angiosperms, which are extant representatives of lineages that diverged the earliest from the lineage leading to the extant mesangiosperms1–3. Here we report the 409-megabase genome sequence of the blue-petal water lily (Nymphaea colorata). Our phylogenomic analyses support Amborellales and Nymphaeales as successive sister lineages to all other extant angiosperms. The N. colorata genome and 19 other water lily transcriptomes reveal a Nymphaealean whole-genome duplication event, which is shared by Nymphaeaceae and possibly Cabombaceae. Among the genes retained from this whole-genome duplication are homologues of genes that regulate flowering transition and flower development. The broad expression of homologues of floral ABCE genes in N. colorata might support a similarly broadly active ancestral ABCE model of floral organ determination in early angiosperms. Water lilies have evolved attractive floral scents and colours, which are features shared with mesangiosperms, and we identified their putative biosynthetic genes in N. colorata. The chemical compounds and biosynthetic genes behind floral scents suggest that they have evolved in parallel to those in mesangiosperms. Because of its unique phylogenetic position, the N. colorata genome sheds light on the early evolution of angiosperms.
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Boyce, C. Kevin, Tim J. Brodribb, Taylor S. Feild, and Maciej A. Zwieniecki. "Angiosperm leaf vein evolution was physiologically and environmentally transformative." Proceedings of the Royal Society B: Biological Sciences 276, no. 1663 (February 25, 2009): 1771–76. http://dx.doi.org/10.1098/rspb.2008.1919.
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The veins that irrigate leaves during photosynthesis are demonstrated to be strikingly more abundant in flowering plants than in any other vascular plant lineage. Angiosperm vein densities average 8 mm of vein per mm 2 of leaf area and can reach 25 mm mm −2 , whereas such high densities are absent from all other plants, living or extinct. Leaves of non-angiosperms have consistently averaged close to 2 mm mm −2 throughout 380 million years of evolution despite a complex history that has involved four or more independent origins of laminate leaves with many veins and dramatic changes in climate and atmospheric composition. We further demonstrate that the high leaf vein densities unique to the angiosperms enable unparalleled transpiration rates, extending previous work indicating a strong correlation between vein density and assimilation rates. Because vein density is directly measurable in fossils, these correlations provide new access to the physiology of extinct plants and how they may have impacted their environments. First, the high assimilation rates currently confined to the angiosperms among living plants are likely to have been unique throughout evolutionary history. Second, the transpiration-driven recycling of water that is important for bolstering precipitation in modern tropical rainforests might have been significantly less in a world before the angiosperms.
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Pegler, Joseph L., Jackson M. J. Oultram, Christopher W. G. Mann, Bernard J. Carroll, Christopher P. L. Grof, and Andrew L. Eamens. "Miniature Inverted-Repeat Transposable Elements: Small DNA Transposons That Have Contributed to Plant MICRORNA Gene Evolution." Plants 12, no. 5 (March 1, 2023): 1101. http://dx.doi.org/10.3390/plants12051101.
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Angiosperms form the largest phylum within the Plantae kingdom and show remarkable genetic variation due to the considerable difference in the nuclear genome size of each species. Transposable elements (TEs), mobile DNA sequences that can amplify and change their chromosome position, account for much of the difference in nuclear genome size between individual angiosperm species. Considering the dramatic consequences of TE movement, including the complete loss of gene function, it is unsurprising that the angiosperms have developed elegant molecular strategies to control TE amplification and movement. Specifically, the RNA-directed DNA methylation (RdDM) pathway, directed by the repeat-associated small-interfering RNA (rasiRNA) class of small regulatory RNA, forms the primary line of defense to control TE activity in the angiosperms. However, the miniature inverted-repeat transposable element (MITE) species of TE has at times avoided the repressive effects imposed by the rasiRNA-directed RdDM pathway. MITE proliferation in angiosperm nuclear genomes is due to their preference to transpose within gene-rich regions, a pattern of transposition that has enabled MITEs to gain further transcriptional activity. The sequence-based properties of a MITE results in the synthesis of a noncoding RNA (ncRNA), which, after transcription, folds to form a structure that closely resembles those of the precursor transcripts of the microRNA (miRNA) class of small regulatory RNA. This shared folding structure results in a MITE-derived miRNA being processed from the MITE-transcribed ncRNA, and post-maturation, the MITE-derived miRNA can be used by the core protein machinery of the miRNA pathway to regulate the expression of protein-coding genes that harbor homologous MITE insertions. Here, we outline the considerable contribution that the MITE species of TE have made to expanding the miRNA repertoire of the angiosperms.
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Boyce, C. Kevin, and Jung-Eun Lee. "An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity." Proceedings of the Royal Society B: Biological Sciences 277, no. 1699 (June 16, 2010): 3437–43. http://dx.doi.org/10.1098/rspb.2010.0485.
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Movement of water from soil to atmosphere by plant transpiration can feed precipitation, but is limited by the hydraulic capacities of plants, which have not been uniform through time. The flowering plants that dominate modern vegetation possess transpiration capacities that are dramatically higher than any other plants, living or extinct. Transpiration operates at the level of the leaf, however, and how the impact of this physiological revolution scales up to the landscape and larger environment remains unclear. Here, climate modelling demonstrates that angiosperms help ensure aseasonally high levels of precipitation in the modern tropics. Most strikingly, replacement of angiosperm with non-angiosperm vegetation would result in a hotter, drier and more seasonal Amazon basin, decreasing the overall area of ever-wet rainforest by 80 per cent. Thus, flowering plant ecological dominance has strongly altered climate and the global hydrological cycle. Because tropical biodiversity is closely tied to precipitation and rainforest area, angiosperm climate modification may have promoted diversification of the angiosperms themselves, as well as radiations of diverse vertebrate and invertebrate animal lineages and of epiphytic plants. Their exceptional potential for environmental modification may have contributed to divergent responses to similar climates and global perturbations, like mass extinctions, before and after angiosperm evolution.
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Harris, Elisha B., and Nan Crystal Arens. "A mid-Cretaceous angiosperm-dominated macroflora from the Cedar Mountain Formation of Utah, USA." Journal of Paleontology 90, no. 4 (July 2016): 640–62. http://dx.doi.org/10.1017/jpa.2016.44.
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AbstractAngiosperms first appeared in the fossil record as pollen during the Valanginian–Hauterivian; they spread out of the tropics in the Aptian and Albian, and radiated in the Late Cretaceous. Despite these general patterns, details of the taxonomic, geographic, and ecological evolution of Cretaceous angiosperms are relatively poorly known because only a handful of Early and mid-Cretaceous macrofloras have been reported. This is the first detailed report of a fossil leaf flora from the Cedar Mountain Formation from the mid-Cretaceous of the Western Interior. We describe a flora that is overwhelmingly dominated by angiosperms (152 of 153 identified specimens are angiosperms) from the Albian–Cenomanian transition that is preserved in a clay- and carbonate-rich, lacustrine mudstone from the uppermost Cedar Mountain Formation of Emery County, Utah. We recognize 18 leaf morphotypes, all of which are dicotyledonous angiosperms. The majority of the Cedar Mountain morphotypes have taxonomic affinities with forms of similar age described from the Atlantic and Gulf coastal plains and other localities from the Western Interior. From this, we infer that a relatively diverse angiosperm flora grew along the margins of a small pond on the coastal plain. Palynological preparations of the fossil matrix were barren; however, previous studies of other facies within the formation showed that both conifers and ferns were important components of the regional vegetation during Cedar Mountain time. The effective absence of conifers and ferns in this macroflora and low leaf mass per area values among the angiosperms measured suggests that even at the Early–Late Cretaceous transition, angiosperms had come to dominate some sites, particularly those that were disturbed or seasonally ephemeral, where fast-growth or seasonal deciduousness would have been favored.
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Masterson, Jane. "The geological history of polyploidy in woody angiosperms." Paleontological Society Special Publications 6 (1992): 203. http://dx.doi.org/10.1017/s2475262200007632.
Full textAbstract:
Polyploidy, the condition where an organism has more than two complete sets of chromosomes, is a common and important evolutionary phenomenon in flowering plants (angiosperms). Estimates of the percentage of angiosperms (approximately 250-300,000 living species) derived from polyploids range from 47-90%. The historical development of polyploidy is currently very poorly understood and whether polyploidy is a major causal factor in angiosperm diversification is widely debated.Many questions about the base chromosome number of angiosperms (important for establishing the extent of polyploidy) and the origin of polyploidy can be addressed using fossil plants. One of the physical effects of polyploidy is a general increase in cell volume; the size of guard cells (leaf epidermal cells that control the opening and closing of the gas exchange pores [stomata]) has been used successfully to determine the relative number of chromosomes present or ploidy level in living Carva (hickories), Betula (birch), Magnolia, and Pvrus (pear). At least two previous studies have used guard cells to estimate ploidy level in fossil taxa (Metasequoia, Sequoia, and Paleorubiaceophyllum).The base haploid chromosome number in angiosperms generally has been assumed to be between n=7-9, but this is apparently based either on the dubious assumption that the most common condition is likely to be primitive (cf. egg laying in mammals) or the inference that because this number is found in many different clades it is likely to be basic in each of these groups. The Gnetales (the living gymnosperms most closely related to angiosperms) have a haploid basic number of 7, but Donoghue and Doyle (1989) find that it is almost equally parsimonious to assume the base number is n=12-14 because of uncertainties over the chromosome number of certain critical extinct outgroups. My guard cell measurements of three angiosperm families (Platanaceae, Magnoliaceae and Lauraceae) provide additional empirical support for the n=7-9 hypothesis and suggest that extinct diploid members existed in the mid-Cretaceous and early Cenozoic floras. These results also falsify the hypothesis that polyploidization triggered the angiosperm radiation in the Cretaceous in these families. Other hypotheses regarding the historical timing of major increases in polyploidy are being tested. These include climatic deterioration and associated modification and mixing of plant distributions during the Eocene and Pleistocene. It may be that polyploids survive major disturbances at a higher rate than diploids because they often have broader ecological tolerances and wider geographic ranges. Thus the accumulation of polyploids in plant families may not occur because they are speciation prone as usually inferred but because they are extinction resistant. My preliminary results in Platanaceae support an increased level of polyploidy after major disturbances.