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1

Wang, Xin. "A Novel Early Cretaceous Flower and Its Implications on Flower Derivation." Biology 11, no. 7 (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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2

Feild, Taylor S., Garland R. Upchurch, David S. Chatelet, et al. "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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3

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 (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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4

Bateman, Richard M. "Hunting the Snark: the flawed search for mythical Jurassic angiosperms." Journal of Experimental Botany 71, no. 1 (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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5

Chopparapu, Chinnappa, Rajanikanth Annamraju, Pauline Sabina Kavali, and ConfiguraçõesSarah Gonçalves Duarte. "Angiosperms from the Early Cretaceous sediments of India." Geologia USP. Série Científica 20, no. 4 (2020): 123–36. http://dx.doi.org/10.11606/issn.2316-9095.v20-171976.

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This study presents the first report of angiosperm macrofossil assemblage from the Early Cretaceous sediments of India, containing a fruit, a spike, a petal, leaves, and an axis from the Krishna Godavari Basin. This assemblage provides clues to angiosperm evolution and ecology during the Early Cretaceous of India. The described enigmatic forms are comparable to fruits of Trapa, and palm leaves and spikes of Potamogeton. The fossil material also includes ribbon-like leaves with a small axis; fossil remains suggest affinity with the monocotyledon group and support recent morphological and molecular phylogenetic studies to establish the divergence of this group from dicotyledons, during the early Cretaceous. Fossils described in the present study suggest an affinity for an aquatic environment that appears to be ideal for some early angiosperms.
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6

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 (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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7

Han, Lei, Ya Zhao, Ming Zhao, Jie Sun, Bainian Sun, and Xin Wang. "New Fossil Evidence Suggests That Angiosperms Flourished in the Middle Jurassic." Life 13, no. 3 (2023): 819. http://dx.doi.org/10.3390/life13030819.

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Angiosperms are a group of plants with the highest rate of evolution, the largest number of species, the widest distribution and the strongest adaptability. Needless to say, angiosperms are the most important group for the humans. The studies on the origin, evolution and systematics of angiosperms have been the major challenges in plant sciences. However, the origin and early history of angiosperms remains poorly understood and controversial among paleobotanists. Some paleobotanists insist that there were no angiosperms in the pre-Cretaceous age. However, this conclusion is facing increasing challenges from fossil evidence, especially Early Jurassic Nanjinganthus, which is based on over two hundred specimens of fossil flowers. Studying more fossil plants is the only reliable way to elucidate the origin and early evolution of angiosperms. Here, we document a new species of angiosperms, Qingganninginfructus formosa gen. et sp. nov, and provide the first detailed three-dimensional morphology of Qingganninginfructus gen. nov from the Middle Jurassic of Northwest China. A Micro-CT examination shows that the best-preserved fossil infructescence has eleven samaroid fruits, each with a single basal ovule. Since these fossils are distinct in morphology and organization from all organs of known gymnosperms and angiosperms (the latter are defined by their enclosed ovules), we interpret Qingganninginfructus as a new genus of angiosperms including a new species, Q. formosa gen. et sp. nov., and an unspecified species from the Middle Jurassic of Northwest China. The discovery of this new genus of angiosperms from the Middle Jurassic, in addition to the existing records, undermines the “no angiosperms until the Cretaceous” stereotype and updates the perspective on the origin and early history of angiosperms.
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8

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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9

Santos, Artai A., and Xin Wang. "Pre-Carpels from the Middle Triassic of Spain." Plants 11, no. 21 (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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10

Wang, Xin. "Origin of Angiosperms: Problems, Challenges, and Solutions." Life 13, no. 10 (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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11

Doyle, James A. "Significance of molecular phylogenetic analyses for paleobotanical investigations on the origin of angiosperms." Journal of Palaeosciences 50, no. (1-3) (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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12

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 (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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13

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 (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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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 (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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Monga, Priyanka, Gaurav Srivastava, Madhav Kumar, and R. C. Mehrotra. "Further palynological investigation of coaliferous sequences of Tura Formation of Nangwalbibra, East Garo Hills, Meghalaya: inferences on palaeovegetation and palaeoclimate." Journal of Palaeosciences 63, no. (1-2) (2014): 79–85. http://dx.doi.org/10.54991/jop.2014.322.

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The coal and carbonaceous shales collected from the Tura Formation (late Palaeocene) of Nangwalbibra, East Garo Hills, Meghalaya, have been analysed for palynological study to deduce palaeovegetation and palaeoclimate. The palynoflora represented by pteridophytic spores and angiospermic pollen grains shows similarity with other contemporaneous deposits of the Garo, Khasi and Jaintia Hills of Meghalaya. The palynoassemblage dominated by angiosperms depicts subtropical to tropical vegetation during the late Palaeocene in the region. The fossil pollen grains show their similarity with modern plants of various tropical angiosperm families, like Alangiaceae, Anacardiaceae, Annonaceae, Arecaceae, Bombacaceae, Clusiaceae and Gunneraceae, etc. which indicate the existence of tropical evergreen to moist deciduous forest. Some of the taxa resemble the floral elements growing near swamps in the tropical zone. The fossil palynoflora indicates warm and humid climate during the depositional period. The study is supported by plant megafossil data known from the same horizon.
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16

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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Bao, Tong, Bo Wang, Jianguo Li, and David Dilcher. "Pollination of Cretaceous flowers." Proceedings of the National Academy of Sciences 116, no. 49 (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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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 (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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Boura, A., G. Saulnier, D. De Franceschi, et al. "An early record of a vesselless angiosperm from the middle Cenomanian of the Envigne valley (Vienne, Western France)." IAWA Journal 40, no. 3 (2019): 530–50. http://dx.doi.org/10.1163/22941932-40190238.

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ABSTRACTThousands of silicified wood fragments were recently collected from the middle Cenomanian of Vienne in western France at less than 10 km away from a historical locality where in 1870 the French geologist Alphonse Le Touzé de Longuemar reported silicified wood. The plant assemblage is very diverse, and includes several species of ferns, conifers, and angiosperms. We describe and discuss the systematic affinities of a new vesselless angiosperm. Many of its characters are shared by extant and fossil Winteraceae. Nevertheless, the absence of uniseriate rays makes the anatomy of these specimens unique. Its combination of characters justifies the establishment of a new genus of vesselless fossil angiosperm wood of uncertain affinity, Sherwinoxylon gen. nov.
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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 (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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Jud, Nathan A., Michael D. D’Emic, Scott A. Williams, Josh C. Mathews, Katie M. Tremaine, and Janok Bhattacharya. "A new fossil assemblage shows that large angiosperm trees grew in North America by the Turonian (Late Cretaceous)." Science Advances 4, no. 9 (2018): eaar8568. http://dx.doi.org/10.1126/sciadv.aar8568.

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The diversification of flowering plants and marked turnover in vertebrate faunas during the mid-Cretaceous transformed terrestrial communities, but the transition is obscured by reduced terrestrial deposition attributable to high sea levels. We report a new fossil assemblage from multiple localities in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale Formation in Utah. The fossils date to the Turonian, a severely underrepresented interval in the terrestrial fossil record of North America. A large silicified log (maximum preserved diameter, 1.8 m; estimated height, ca. 50 m) is assigned to the genusParaphyllanthoxylon; it is the largest known pre-Campanian angiosperm and the earliest documented occurrence of an angiosperm tree more than 1.0 m in diameter. Foliage and palynomorphs of ferns, conifers, and angiosperms confirm the presence of mixed forest or woodland vegetation. Previously known terrestrial vertebrate remains from the Ferron Sandstone Member include fish teeth, two short dinosaur trackways, and a pterosaur; we report the first turtle and crocodilian remains and an ornithopod sacrum. Previous studies indicate that angiosperm trees were present by the Cenomanian, but this discovery demonstrates that angiosperm trees approaching 2 m in diameter were part of the forest canopies across southern North America by the Turonian (~92 million years ago), nearly 15 million years earlier than previously thought.
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22

Wheeler, Elisabeth A., Peter K. Brown, and Allan J. Koch. "Late Paleocene woods from Cherokee Ranch, Colorado, U.S.A." Rocky Mountain Geology 54, no. 1 (2019): 33–46. http://dx.doi.org/10.24872/rmgjournal.54.1.33.

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ABSTRACT Fossil woods are common in the Late Cretaceous through early Eocene rocks of the Denver Basin, Colorado. The overwhelming majority of these woods are dicotyledonous angiosperms. A new locality for fossil woods, Cherokee Ranch, in the upper D1 stratigraphic sequence (Denver Formation) is described, and evidence for it being late Paleocene is reviewed. Most Cherokee Ranch woods resemble previously described Denver Basin angiosperm woods, but there is one new type of wood attributed to the family Lauraceae. A new genus, Ubiquitoxylon, is proposed for woods with the combination of features commonly seen in the Cherokee Ranch woods. Denver Basin Paleocene woods differ from Paleocene wood assemblages to the north (Wyoming and Montana), where conifer woods are common and angiosperms are rare. The width and spacing of the water-conducting vessels and the lack of distinct growth rings in almost all of the Cherokee Ranch woods suggest that these trees did not experience water stress, and there was no pronounced seasonality.
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23

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 (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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24

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 (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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Sharma, B. D., D. R. Bohra, and O. P. Suthar. "Some interesting plant fossils from the Mesozoic of the Rajmahal Hills, India." Journal of Palaeosciences 50, no. (1-3) (2001): 207–12. http://dx.doi.org/10.54991/jop.2001.1823.

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Description is given of some interesting plant fossils preserved as petrifactions in the Rajmahal Hills, Jharkhand. These are either new and reponed for the first time or an additional information is given on already known earlier description. The fossil taxa belong to algae, lichen, gymnosperms and angiosperms.
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Kvaček, Jiří, and Jakub Sakala. "Late Cretaceous flora of James Ross Island (Antarctica) – preliminary report." Czech Polar Reports 1, no. 2 (2011): 96–103. http://dx.doi.org/10.5817/cpr2011-2-9.

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Fossil plants from Late Cretaceous strata (Hidden Lake Formation and Santa Marta Formation) of James Ross Basin exposed in the northern part of the James Ross Island are preliminary described. Both formations contain plant mega fossils, petrified wood, and charcoalified mesofossils. Fossil plants from the Hidden Lake Formation are represented by leaf impressions of pteridophytes (Microphyllopteris, Delosorus, Lygodium), conifers (Elatocladus, Brachyphyllum, Pagiophyllum, Araucaria, Podozamites vel Lindleycladus), Bennettitales vel Cycadales (Zamites vel Dioonites sp.) and angiosperms (Cinnamomoides, Dicotylophyllum ssp., Proteophyllum, Juglandi-phyllum vel Dicotylophyllum). Fossil wood can be attributed to the very broadly defined morphogenus Antarctoxylon Poole & Cantrill.
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27

Lupia, Richard, Scott Lidgard, and Peter R. Crane. "Comparing palynological abundance and diversity: implications for biotic replacement during the Cretaceous angiosperm radiation." Paleobiology 25, no. 3 (1999): 305–40. http://dx.doi.org/10.1017/s009483730002131x.

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The Cretaceous radiation of angiosperms initiated a major reorganization of terrestrial plant communities as dominance by pteridophytic and gymnospermic groups eventually gave way to dominance by angiosperms. Previously, patterns of biotic replacement have been assessed using measures based on taxonomic diversity data. However, using measures of both abundance and diversity to investigate replacement patterns provides more information about macroecological change in the fossil record than either can provide alone. Analyses of an updated and expanded database of North American palynological samples from Cretaceous sediments document a rapid increase in angiosperm diversity and abundance within individual fossil palynofloras (representing local/subregional vegetation). New analyses of floristic diversity patterns support previous results and indicate that the decline of free-sporing plants is more pronounced than the decline of gymnosperms. In contrast, analyses of abundance data appear to show that the decline of gymnosperms is far more pronounced than the decline of free-sporing plants. Detailed examination of both data sets segregated by paleolatitude shows that this apparent contradiction reflects biogeographical differences in the patterns of vegetational change (e.g., free-sporing plants declined in abundance at lower latitudes) as well as sampling bias (e.g., greater sampling in the northern region in the Late Cretaceous). Analyses accounting for these biases support the conclusion that as angiosperms radiated, free-sporing plants rather than gymnosperms (in this case, mainly conifers) experienced the most pronounced decline. A thorough understanding of the Cretaceous radiation of angiosperms will require both abundance and diversity data. It also will require expanding the analyses presented here into other geographic regions as well as sampling more completely at all spatial scales.
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28

Masterson, Jane. "The geological history of polyploidy in woody angiosperms." Paleontological Society Special Publications 6 (1992): 203. http://dx.doi.org/10.1017/s2475262200007632.

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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.
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Condamine, Fabien L., Daniele Silvestro, Eva B. Koppelhus, and Alexandre Antonelli. "The rise of angiosperms pushed conifers to decline during global cooling." Proceedings of the National Academy of Sciences 117, no. 46 (2020): 28867–75. http://dx.doi.org/10.1073/pnas.2005571117.

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Competition among species and entire clades can impact species diversification and extinction, which can shape macroevolutionary patterns. The fossil record shows successive biotic turnovers such that a dominant group is replaced by another. One striking example involves the decline of gymnosperms and the rapid diversification and ecological dominance of angiosperms in the Cretaceous. It is generally believed that angiosperms outcompeted gymnosperms, but the macroevolutionary processes and alternative drivers explaining this pattern remain elusive. Using extant time trees and vetted fossil occurrences for conifers, we tested the hypotheses that clade competition or climate change led to the decline of conifers at the expense of angiosperms. Here, we find that both fossil and molecular data show high congruence in revealing 1) low diversification rates, punctuated by speciation pulses, during warming events throughout the Phanerozoic and 2) that conifer extinction increased significantly in the Mid-Cretaceous (100 to 110 Ma) and remained high ever since. Their extinction rates are best explained by the rise of angiosperms, rejecting alternative models based on either climate change or time alone. Our results support the hypothesis of an active clade replacement, implying that direct competition with angiosperms increased the extinction of conifers by pushing their remaining species diversity and dominance out of the warm tropics. This study illustrates how entire branches on the Tree of Life may actively compete for ecological dominance under changing climates.
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Sakala, Jakub, and Radek Vodrážka. "A new species of Antarctoxylon: a contribution to the early angiosperm ecosystem of Antarctica during the late Cretaceous." Antarctic Science 26, no. 4 (2013): 371–76. http://dx.doi.org/10.1017/s095410201300076x.

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AbstractA new species of Antarctoxylon is described from the Coniacian Hidden Lake Formation of James Ross Island as A. mixai Sakala, sp. nov. This angiosperm fossil wood shows a unique combination of features in having indistinct growth ring boundaries, scalariform perforation plates with about 30 bars and rays both narrow (1–6-seriate) and very wide (up to 18-seriate). Its systematic affinities and exact living relative at the specific, generic or even familial level cannot be specified. Along with Weinmannioxylon nordenskjoeldii from James Ross Island and the angiosperm woods from the Williams Point on Livingston Island, this record provides further evidence of the earliest record of arboreal angiosperms in Antarctica.
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31

Heřmanová, Zuzana, Jiří Kvaček, and Else Marie Friis. "Plant mesofossils from the Late Cretaceous Klikov Formation, the Czech Republic." Fossil Imprint 77, no. 2 (2021): 256–70. http://dx.doi.org/10.37520/fi.2021.018.

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Late Cretaceous mesofossils are described from the Zliv-Řídká Blana locality in the South Bohemian Basins, the Czech Republic. Angiosperm remains dominate the fossil assemblage both in terms of taxonomic diversity and quantitatively, with about 65 different species based on about 1,000 specimens of flowers, fruits and seeds. There are surprisingly few nonangiosperm species in the flora, with only four specimens assigned to bryophytes, ferns and conifers. There are no megaspores of Selaginellales or Salviniales, which are otherwise common in many Cretaceous mesofossil floras. Among angiosperms, flowers and fruits assigned to the Normapolles group (Fagales) and to the Ericales are particularly prominent. In systematic composition as well as general organization and size of the angiosperm reproductive organs, the Zliv-Řídká Blana mesofossil flora is comparable to other Late Cretaceous mesofossil floras collected from various regions of Laurasia. In addition to the plant remains, the fossil assemblage also includes insect eggs and coprolites.
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Friis, Else Marie, Peter R. Crane, and Kaj Raunsgaard Pedersen. "Multiparted, apocarpous flowers from the Early Cretaceous of eastern North America and Portugal." Fossil Imprint 76, no. 2 (2020): 279–96. http://dx.doi.org/10.37520/fi.2020.023.

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Three new genera, Atlantocarpus, Lambertiflora and Mugideiriflora, are described from the Early Cretaceous of North America and Portugal based on floral structures with multicarpellate and apocarpous gynoecia that have been studied using scanning electron microscopy and synchrotron radiation X-ray tomographic microscopy. Lambertiflora and Mugideiriflora have numerous perianth parts in several series, as well as many stamens and many carpels borne on a short conical receptacle. Atlantocarpus has many carpels arranged spirally on an elongated receptacle. Perianth and stamens are not preserved in Atlantocarpus, but scars of two sizes at the base of the receptacle indicate the presence of several series of tepals and stamens. Phylogenetic assessment of the three new genera indicates close relationships with members of extant Austrobaileyales, which is also favoured by the apparently ascidiate carpels of Atlantocarpus. However, the phylogenetic signal is not strong and the fossils also share many features with magnoliid angiosperms. Fully secure resolution of their relationships is hampered by lack of information of critical floral features in the fossil material, the constellation of likely plesiomorphic characters that they exhibit, and inadequate knowledge of character homologies and character evolution among extant taxa. There is also the broader concern about whether phylogenetic patterns can be reliably inferred for the earliest phases of angiosperm evolution based solely on a depauperate assemblage of extant taxa given extensive extinction over the last 100 million years. The new genera add to growing evidence of diverse extinct angiosperms with multiparted flowers during the Early Cretaceous that have a variety of relationships to extant ANA-grade angiosperms and magnoliids.
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33

Gomez, Bernard, Véronique Daviero-Gomez, Clément Coiffard, Carles Martín-Closas, and David L. Dilcher. "Montsechia, an ancient aquatic angiosperm." Proceedings of the National Academy of Sciences 112, no. 35 (2015): 10985–88. http://dx.doi.org/10.1073/pnas.1509241112.

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The early diversification of angiosperms in diverse ecological niches is poorly understood. Some have proposed an origin in a darkened forest habitat and others an open aquatic or near aquatic habitat. The research presented here centers on Montsechia vidalii, first recovered from lithographic limestone deposits in the Pyrenees of Spain more than 100 y ago. This fossil material has been poorly understood and misinterpreted in the past. Now, based upon the study of more than 1,000 carefully prepared specimens, a detailed analysis of Montsechia is presented. The morphology and anatomy of the plant, including aspects of its reproduction, suggest that Montsechia is sister to Ceratophyllum (whenever cladistic analyses are made with or without a backbone). Montsechia was an aquatic angiosperm living and reproducing below the surface of the water, similar to Ceratophyllum. Montsechia is Barremian in age, raising questions about the very early divergence of the Ceratophyllum clade compared with its position as sister to eudicots in many cladistic analyses. Lower Cretaceous aquatic angiosperms, such as Archaefructus and Montsechia, open the possibility that aquatic plants were locally common at a very early stage of angiosperm evolution and that aquatic habitats may have played a major role in the diversification of some early angiosperm lineages.
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Near, Thomas J., and Michael J. Sanderson. "Assessing the quality of molecular divergence time estimates by fossil calibrations and fossil–based model selection." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 359, no. 1450 (2004): 1477–83. http://dx.doi.org/10.1098/rstb.2004.1523.

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Estimates of species divergence times using DNA sequence data are playing an increasingly important role in studies of evolution, ecology and biogeography. Most work has centred on obtaining appropriate kinds of data and developing optimal estimation procedures, whereas somewhat less attention has focused on the calibration of divergences using fossils. Case studies with multiple fossil calibration points provide important opportunities to examine the divergence time estimation problem in new ways. We discuss two cross–validation procedures that address different aspects of inference in divergence time estimation. ‘Fossil cross–validation’ is a procedure used to identify the impact of different individual calibrations on overall estimation. This can identify fossils that have an exceptionally large error effect and may warrant further scrutiny. ‘Fossil–based model cross–validation’ is an entirely different procedure that uses fossils to identify the optimal model of molecular evolution in the context of rate smoothing or other inference methods. Both procedures were applied to two recent studies: an analysis of monocot angiosperms with eight fossil calibrations and an analysis of placental mammals with nine fossil calibrations. In each case, fossil calibrations could be ranked from most to least influential, and in one of the two studies, the fossils provided decisive evidence about the optimal molecular evolutionary model.
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Zhi–chen, Song, Wang Wei–ming, and Huang Fei. "Fossil Pollen Records of Extant Angiosperms in China." Botanical Review 70, no. 4 (2004): 425–58. http://dx.doi.org/10.1663/0006-8101(2004)070[0425:fproea]2.0.co;2.

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36

Gottschling, M., and H. H. Hilger. "First fossil record of transfer cells in angiosperms." American Journal of Botany 90, no. 6 (2003): 957–59. http://dx.doi.org/10.3732/ajb.90.6.957.

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37

Ahrens, Dirk, Julia Schwarzer, and Alfried P. Vogler. "The evolution of scarab beetles tracks the sequential rise of angiosperms and mammals." Proceedings of the Royal Society B: Biological Sciences 281, no. 1791 (2014): 20141470. http://dx.doi.org/10.1098/rspb.2014.1470.

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Extant terrestrial biodiversity arguably is driven by the evolutionary success of angiosperm plants, but the evolutionary mechanisms and timescales of angiosperm-dependent radiations remain poorly understood. The Scarabaeoidea is a diverse lineage of predominantly plant- and dung-feeding beetles. Here, we present a phylogenetic analysis of Scarabaeoidea based on four DNA markers for a taxonomically comprehensive set of specimens and link it to recently described fossil evidence. The phylogeny strongly supports multiple origins of coprophagy, phytophagy and anthophagy. The ingroup-based fossil calibration of the tree widely confirmed a Jurassic origin of the Scarabaeoidea crown group. The crown groups of phytophagous lineages began to radiate first (Pleurostict scarabs: 108 Ma; Glaphyridae between 101 Ma), followed by the later diversification of coprophagous lineages (crown-group age Scarabaeinae: 76 Ma; Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62 Ma in the oldest anthophagous lineage. The clear time lag between the origins of herbivores and coprophages suggests an evolutionary path driven by the angiosperms that first favoured the herbivore fauna (mammals and insects) followed by the secondary radiation of the dung feeders. This finding makes it less likely that extant dung beetle lineages initially fed on dinosaur excrements, as often hypothesized.
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38

Sgorbati, Sergio, Marco D'Antraccoli, Sandra Citterio, Rodolfo Gentili, and Lorenzo Peruzzi. "Was Charles Darwin right in his explanation of the ‘abominable mystery’?" Italian Botanist 5 (March 13, 2018): 25–30. http://dx.doi.org/10.3897/ib.5.24699.

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The site and time of origin of angiosperms are still debated. The co-occurrence of many of the early branching lineages of flowering plants in a region somewhere between Australia and the SW Pacific islands suggests a possible Gondwanan origin of angiosperms. The recent recognition of Zealandia, a 94% submerged continent in the east of Australia, could explain the discrepancy between molecular clocks and fossil records about the age of angiosperms, supporting the old Darwinian hypothesis of a “lost continent” to explain the “abominable mystery” regarding the origin and rapid radiation of flowering plants.
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39

Sgorbati, Sergio, Marco D'Antraccoli, Sandra Citterio, Rodolfo Gentili, and Lorenzo Peruzzi. "Was Charles Darwin right in his explanation of the ‘abominable mystery’?" Italian Botanist 5 (March 13, 2018): 25–30. http://dx.doi.org/10.3897/italianbotanist.5.24699.

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The site and time of origin of angiosperms are still debated. The co-occurrence of many of the early branching lineages of flowering plants in a region somewhere between Australia and the SW Pacific islands suggests a possible Gondwanan origin of angiosperms. The recent recognition of Zealandia, a 94% submerged continent in the east of Australia, could explain the discrepancy between molecular clocks and fossil records about the age of angiosperms, supporting the old Darwinian hypothesis of a “lost continent” to explain the “abominable mystery” regarding the origin and rapid radiation of flowering plants.
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40

Shields, Oakley. "The origin and initial radiation of angiosperms In relation to anthophytes." Journal of Palaeosciences 42, no. 1-3 (1993): 157–68. http://dx.doi.org/10.54991/jop.1993.1142.

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Autapomorphics indicate the angiosperms form a monophyletic group. Analysis of Aptian-Cenomanian macrofossils establishes that Chloranthaceae holds a central position in the initial radiation of dicots. While Palmae was basal to monocot initial radiation in the Maastrichtian. By tracing their fossil pollen back in time, two lines probably arose from two different species of Monocrinopollis (Crinopolles Group) in the Norian (Upper Triassic) The Crinopolles Group were extinct angiosperms that evolved directly from Steevesipollenites (Gnetales). The origin and initial radiation of angiosperms occurred in North America under stress habitat conditions. Glossopteridales, Caytoniales and Bennettitales display extreme convergent tendencies to angiosperms, while Gnetales similarities to angiosperms are more numerous and fundamental. Gnetales-angiosperms and Bennettitales-Pentoxylales evolved as two distinct lines of anthophytes. Bennettitales arose from Gangamopteris (Glossopteirdales) in the Lower Permian of South Africa, while Gnetales evolved either from Bennettitales or Glossopteridales at that time, also in South Africa.
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41

Crepet, William L. "The Fossil Record of Angiosperms: Requiem or Renaissance?1." Annals of the Missouri Botanical Garden 95, no. 1 (2008): 3–33. http://dx.doi.org/10.3417/2007065.

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42

Doyle, James A. "Molecular and Fossil Evidence on the Origin of Angiosperms." Annual Review of Earth and Planetary Sciences 40, no. 1 (2012): 301–26. http://dx.doi.org/10.1146/annurev-earth-042711-105313.

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43

Pant, D. D., and Rita Singh. "Possible fossil sporae dispersae of hepaticae and anthocerotales in the fossil records." Journal of Palaeosciences 39, no. (1-3) (1990): 20–36. http://dx.doi.org/10.54991/jop.1990.1679.

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The paper attempts to find the characters which can distinguish the spores of Hepaticae and Anthocerotales from iso- or micro-spores of pteridophytes and pollen grains of gymnosperms and angiosperms for the identification of possible fossil Sporae dispersae of bryophytes reported from different geological horizons. The problem was approached by looking for characters in fossil spores which are (i) exclusively bryophytic, (ii) prevailingly bryophytic, and (iii) closely matching characters of in situ spores of fossil bryophytes in a first-hand comparison. Our account also takes into consideration the Sporae dispersae which were described or suspected by previous workers as those of bryophytes but which could equally well belong to pteridophytes.
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Doweld, Alexander B. "Boreocarya and Globocarya, new names in the extinct Juglandaceae of Northern Eurasia." Acta Palaeobotanica 56, no. 2 (2016): 519–21. http://dx.doi.org/10.1515/acpa-2016-0010.

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Abstract Sphaerocarya Dorofeev 1970, being a junior homonym of extant angiosperms Sphaerocarya Wallich 1827 (Santalaceae) and Sphaerocarya Dalzell ex de Candolle 1857 (Olacaceae), is replaced by a new name, Globocarya Doweld nom. nov. (fossil Juglandaceae). The aberrant fossil species Sphaerocarya uralensis Dorofeev is re-classified and segregated into a new distinct genus, Boreocarya Doweld, gen. nov.
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LIMA, FLAVIANA J. DE, ANTÔNIO A. F. SARAIVA, MARIA A. P. DA SILVA, RENAN A. M. BANTIM, and JULIANA M. SAYÃO. "A new angiosperm from the Crato Formation (Araripe Basin, Brazil) and comments on the Early Cretaceous Monocotyledons." Anais da Academia Brasileira de Ciências 86, no. 4 (2014): 1657–72. http://dx.doi.org/10.1590/0001-3765201420140339.

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The Crato Formation paleoflora is one of the few equatorial floras of the Early Cretaceous. It is diverse, with many angiosperms, especially representatives of the clades magnoliids, monocotyledons and eudicots, which confirms the assumption that angiosperm diversity during the last part of the Early Cretaceous was reasonably high. The morphology of a new fossil monocot is studied and compared to all other Smilacaceae genus, especially in the venation. Cratosmilax jacksoni gen. et sp. nov. can be related to the Smilacaceae family, becoming the oldest record of the family so far. Cratosmilax jacksoni is a single mesophilic leaf with entire margins, ovate shape, with acute apex and base, four venation orders and main acrodromous veins. It is the first terrestrial monocot described for the Crato Formation, monocots were previously described for the same formation, and are considered aquatics. Cratosmilax jacksoni is the first fossil record of Smilacaceae in Brazil, and the oldest record of this family.
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46

Nunes, Cristina I., Roberto R. Pujana, Ignacio H. Escapa, María A. Gandolfo, and N. Rubén Cúneo. "A new species of Carlquistoxylon from the Early Cretaceous of Patagonia (Chubut province, Argentina): the oldest record of angiosperm wood from South America." IAWA Journal 39, no. 4 (2018): 406–26. http://dx.doi.org/10.1163/22941932-20170206.

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ABSTRACTAn angiospermous wood from the Lower Cretaceous (upper Albian) of the Cerro Barcino Formation, Chubut Group, central Patagonia, Argentina, is described. Its estimated minimum diameter is 40 cm and it is significant as the oldest known angiosperm wood for South America.It has indistinct growth ring boundaries, vessels solitary and in radial multiples, simple perforation plates, alternate intervessel pits, vessel-ray parenchyma pits oval to horizontally elongated, heterocellular rays, non-septate fibres, axial parenchyma absent, and abundant tyloses. Because this Albian wood has non-septate fibres we assign it to Carlquistoxylon, even though it has a general combination of characters similar to that of Paraphyllanthoxylon, which has septate fibres. The number of vessels per radial multiple, vessel tangential diameter and frequency, vessel-ray parenchyma pitting, and absence of axial parenchyma distinguish the fossil described here from the only previously known species of Carlquistoxylon: Carlquistoxylon nacimientense; therefore, a new species is erected. Because of the close similarities between this new specimen and Paraphyllanthoxylon species, comparisons with all the species included in both genera are provided. Systematic affinities for this wood are discussed considering previous discussions for both Paraphyllanthoxylon and Carlquistoxylon affinities. As the oldest described angiosperm wood in South America to date, this specimen provides critical information on the diversity and growth habit of Cretaceous angiosperms from the Southern Hemisphere.
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47

Guleria, J. S., R. K. Hemanta Singh, R. C. Mehrotra, I. Soibam, and Rajkumar Kishor. "Palaeogene plant fossils of Manipur and their palaeoecological significance." Journal of Palaeosciences 54, no. (1-3) (2005): 61–77. http://dx.doi.org/10.54991/jop.2005.69.

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The paper describes for the first time some Palaeogene plant fossils from Manipur, Northeast India. The fossils were recovered from the late Eocene and early Oligocene sediments in the vicinity of the boundary of the Disang and Barail Groups of rocks of the Imphal Valley and its adjoining areas. All the fossils belong to Angiosperms and represent monocots and dicots. The assemblage consists of mainly dicotyledonous leaves, two types of palm leaves, a fruiting shoot, a leguminous fruit and a bark. The fossil leaves show a rich morphological diversity and indicate the existence of warm and humid tropical vegetation at the time of deposition.
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48

Agarwal, A. "Angiospermous fossil fruits/seeds during Tertiary in India." Journal of Palaeosciences 57, no. (1-3) (2008): 165–75. http://dx.doi.org/10.54991/jop.2008.234.

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A number of fossil fruits/seeds are known from the different Tertiary sediments in India ranging from the Maastrichtian-Danian (Palaeocene) to the Pliocene-Pleistocene. Present account embodies the listing of some well-known fossil fruits/seeds from the Indian Tertiary and an attempt has been made to throw light on their palaeoecological, palaeophytogeographical and the evolutionary significance. Most of the known monocot fossils belong particularly to the family Arecaceae from the Maastrichtian-Danian Deccan Intertrappean beds of India. In the dicots, quite a few fossil fruits/seeds of family Lythraceae are described only from the Maastrichtian-Danian, while the fabaceous fruits/seeds are described in a large number mostly from the Oligocene to Miocene. The families viz., Arecaceae, Burseraceae, Combretaceae, Nyssaceae, Polygonaceae, Rhamnaceae, Rubiaceae and Sapindaceae occur in the Neogene sediments. However, the paucity of fossil fruits/seeds precludes any definite analysis or comments on their palaeobotanical characteristics. Most of the fossil fruits are drupaceous or capsular while fabaceous fruits are lomentum or legume. types. The fibrous nature of mesocarp in Arecaceous fruits suggests their dispersal through water, such plants might be growing in the coastal areas or near the other water bodies. The capsular or the other fruits with thin pericarp might belong to the inland terrestrial zones. Many fruits of uncertain affinities, e.g. Sahniocarpon, Wingospermocarpon, Enigmocarpon and Viracarpon pose interesting questions about the evolution of angiosperms during the Tertiary in India. Further investigations are needed to ascertain the taxonomy of fossil fruits/seeds, to ascribe them to respective families. Key-words—, , ,
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49

Boyce, C. Kevin. "The Fossil Record of Plant Physiology and Development—What Leaves Can Tell Us." Paleontological Society Papers 14 (October 2008): 133–46. http://dx.doi.org/10.1017/s1089332600001650.

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Plants provide unmatched opportunities to evaluate long debated evolutionary patterns in terms of the detailed biology of the fossil organisms. Leaves serve here as an example of how those advantages can be exploited. Over the history of vascular plants, three important transitions in leaf evolution—the origin of laminate leaves, the progressive loss of seed plant morphological diversity, and the evolution of more angiosperm-like leaves—also represent major shifts in leaf development and physiology. These transitions often occurred in parallel in different lineages, such as the evolution of marginal growth in each of at least four independent origins of laminate leaves during the Devonian and Carboniferous. Each also entailed dramatic reorganizations of leaf hydraulics. For example, the length of the finest distributary vein order varies from up to tens of centimeters down to hundreds of microns in successive groups of dominant seed plants. Angiosperms impose an additional trend upon these patterns with the evolution of their uniquely high vein densities. Vein density strongly influences and can provide a proxy for other physiological characteristics, such as assimilation and transpiration rates. The large increase in transpiration capacity accompanying the evolution of angiosperm leaf traits may even play an important role in feeding precipitation and thereby altering local climate.
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50

Coiro, Mario, Guillaume Chomicki, and James A. Doyle. "Experimental signal dissection and method sensitivity analyses reaffirm the potential of fossils and morphology in the resolution of the relationship of angiosperms and Gnetales." Paleobiology 44, no. 3 (2018): 490–510. http://dx.doi.org/10.1017/pab.2018.23.

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AbstractThe placement of angiosperms and Gnetales in seed plant phylogeny remains one of the most enigmatic problems in plant evolution, with morphological analyses (which have usually included fossils) and molecular analyses pointing to very distinct topologies. Almost all morphology-based phylogenies group angiosperms with Gnetales and certain extinct seed plant lineages, while most molecular phylogenies link Gnetales with conifers. In this study, we investigate the phylogenetic signal present in published seed plant morphological data sets. We use parsimony, Bayesian inference, and maximum-likelihood approaches, combined with a number of experiments with the data, to address the morphological–molecular conflict. First, we ask whether the lack of association of Gnetales with conifers in morphological analyses is due to an absence of signal or to the presence of competing signals, and second, we compare the performance of parsimony and model-based approaches with morphological data sets. Our results imply that the grouping of Gnetales and angiosperms is largely the result of long-branch attraction (LBA), consistent across a range of methodological approaches. Thus, there is a signal for the grouping of Gnetales with conifers in morphological matrices, but it was swamped by convergence between angiosperms and Gnetales, both situated on long branches. However, this effect becomes weaker in more recent analyses, as a result of addition and critical reassessment of characters. Even when a clade including angiosperms and Gnetales is still weakly supported by parsimony, model-based approaches favor a clade of Gnetales and conifers, presumably because they are more resistant to LBA. Inclusion of fossil taxa weakens rather than strengthens support for a relationship of angiosperms and Gnetales. Our analyses finally reconcile morphology with molecules in favoring a relationship of Gnetales to conifers, and show that morphology may therefore be useful in reconstructing other aspects of the phylogenetic history of the seed plants.
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