Sborník Národního muzea v Praze. Řada B, Přírodní vědy, Dec 20, 2014
A new fossil eusporangiate fern Marattiopsis vodrazkae J. Kvaček, sp. nov. has been recovered fro... more A new fossil eusporangiate fern Marattiopsis vodrazkae J. Kvaček, sp. nov. has been recovered from the Hidden Lake Formation, the Campanian of James Ross Island, Antarctica. Its fertile and sterile pinnules are described and compared to the other species of the fossil genus Marattiopsis Schimper and the living genera Marattia, Ptisana and Eupodium (Marattiaceae). In contrast to the other species of the genus Marattiopsis, M. vodrazkae is characterised by stalked synangia, a smaller number of sporangia per synangium, generally small sized pinnules, and the absence of venuli recurrentes. It shows a mosaic of characters present in the living Marattiaceae: it shares stalked sporangia with the genus Eupodium and some species of Marattia and exhibits a suture (an abscission scar at pinnule bases), a character typical for the genus Ptisana. Additionally, M. vodrazkae provides important palaeoenvironmental signals for climate reconstructions, arguing for warm (paratropical to warm-temperate) and humid climatic conditions on the Antarctic Peninsula and adjacent volcanic islands during the Campanian.
Palaeobiodiversity and Palaeoenvironments, Dec 10, 2023
A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of ... more A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of Slovakia. It comes from the Mráznica Formation of the Rajec Basin in Fatricum, Zbyňov locality, Rajecké Teplice (Žilina district). The presence of a 53 mm long horsetail axis provides good evidence of terrestrial environments during sedimentation of the studied strata. According to our interpretation, such a plant strongly indicates a moist to wet habitat (even swampy environments) on the presumed dryland from where it was transported. This dryland could represent an isolated unknown small island(s) in the vicinity, or the Vindelician-Bohemian Massif that was active as a dryland for the entire period of time from the Triassic through the Late Cretaceous. However, the exact palaeogeographic position of the Fatricum during the Mesozoic in relation to the Vindelician Landmass is not entirely clear, and such an interpretation needs a bit of caution.
Review of Palaeobotany and Palynology, Nov 1, 2020
Three types of charcoalified fossil homoxylous woods are described from the Upper Cretaceous of t... more Three types of charcoalified fossil homoxylous woods are described from the Upper Cretaceous of the Bohemian Cretaceous Basin: Podocarpoxylon sp.,?Podocarpoxylon vel Taxodioxylon sp. and Protocupressinoxylon sp. They come from the uppermost part of the Peruc-Korycany Formation, which is mid-Cenomanian in age. Podocarpoxylon sp. shows distinct growth rings, uniseriate rays of medium height, 1-2 podocarpoid cross-field pits, and abietinean pitting on radial tracheid walls. Wood of ?Podocarpoxylon vel Taxodioxylon sp. differs in its indistinct growth rings, its rays which are uniseriate with medium height to multiseriate with horizontal resin duct, 1-2 podocarpoid cross-field pits per field, and mixed type of pitting on its radial tracheid walls. Protocupressinoxylon sp. also displays indistinct growth rings, and its rays are either uniseriate of medium height or multiseriate with horizontal resin ducts, but it has 1, occasionally 2-3 cupressoid cross-field pits per field, and abietinean to mixed pitting on radial tracheid walls. One of the three woods shows wood with growth rings, suggesting seasonally dry climate. The composition of the wood assemblage and its comparison with plant megafossils, sporomorphs and sedimentology suggest that there are two paleoenvironments in Unit 5 of the Peruc-Korycany Formation in the Pecínov quarry: a swampy coniferous forest in the coastal lowlands, and a mesophytic forest in the uplands.
Review of Palaeobotany and Palynology, Dec 1, 2021
Abstract A new cheirolepidiaceous conifer Watsoniocladus cunhae sp. nov. J.Kvacek et M.M.Mendes i... more Abstract A new cheirolepidiaceous conifer Watsoniocladus cunhae sp. nov. J.Kvacek et M.M.Mendes is described from the Early Cretaceous of Catefica in the Lusitanian Basin, Estremadura region, western Portugal. The new species Watsoniocladus cunhae has been established based on sterile twigs showing decussately arranged s-shaped leaves equipped with stomata surrounded by papillae and arranged in short rows. The new species is compared to all already-published species assigned to Watsoniocladus. Additionally, based on the newly observed morphological features in the Portuguese material (cuticle characters), we transfer two species from Cupressinocladus (Cupressaceae) to Watsoniocladus (Cheirolepidiaceae): Watsoniocladus itieri (Saporta) comb. nov. from the late Kimmeridgian of southern Jura (France) and Watsoniocladus crassirameus (Zheng Y.Cao) comb. nov. from the Early Cretaceous of China.
The Late Cretaceous flora of the Klikov Formation (Upper Turonian-Santonian) in South Bohemia com... more The Late Cretaceous flora of the Klikov Formation (Upper Turonian-Santonian) in South Bohemia comprises 110 species representing pteridophytes, ferns, conifers, angiosperms, macro and mesofossils. Palaeoclimatic analysis of the Klikov Formation Flora using methods of Leaf Margin Analysis, Climate Leaf Analysis Multivariate Program (CLAMP) and the Nearest Living Relative allows us to conclude that this flora experienced a seasonally dry subtropical climate. Mean annual temperature is predicted to have been approximately 15°C. Numerous charcoalified fossils strongly suggest frequent fires typical of a seasonally dry climate.
Araucarian pollen cones Rabagostrobus hispanicus gen. et sp. nov. and their associated foliage Br... more Araucarian pollen cones Rabagostrobus hispanicus gen. et sp. nov. and their associated foliage Brachyphyllum obesum Heer are described from Lower Cretaceous (Albian) strata of northern Spain. Male cones consist of helically arranged microsporophylls bearing 5-8 elongate pollen sacs with in situ inaperturate Araucariacites-type pollen. The new taxon is compared to material described previously from the Early Cretaceous of North and South Americas. Sterile twigs of B. obesum bear helically arranged leaves with wrinkled margins. Its cuticle has files of predominantly transversely oriented stomata. Both twigs and pollen cones occur as inclusions in amber from the Peñacerrada 1 outcrop (Alava Province), and as compressions are recorded from the amber-bearing strata sediments of the R abago/El Soplao outcrop. Inclusions of araucariacean plant remains and the co-occurrence of amber and male cone and twig compressions suggest that the amber in these two localities, or at least some of it, was produced by araucariacean plants.
Springer Textbooks in Earth Sciences, Geography and Environment, 2020
Flowering plants, the angiosperms, are the most diverse group of plants on our planet. Today, the... more Flowering plants, the angiosperms, are the most diverse group of plants on our planet. Today, they dominate most vegetation types, but their origen continues to remain a mystery. However, we continue to gain knowledge about their early evolution and history. It seems increasingly probable that their origen is associated with climatic and environmental changes in tropical areas and was coeval with the breakup of the supercontinent Gondwana. The first angiosperms appeared in the fossil record about 135 million years ago based on the occurrence of their rare pollen grains in fossil assemblages of North Gondwana and southwest Europe. Their evolution may be associated with climate perturbation and an overall change in wetland to mesophytic habitats, as this group is adapted to tolerate a seasonally dry climate. Soon after the first early angiosperms in the late Valanginian, higher angiosperms, the eudicots, are part of the fossil record of Africa. These initial flowering plants had small inconspicuous flowers and small fruits, and were most probably of small growth stature, likely herbs and shrubs. After angiosperms colonized mineral soils across the landscape, they expanded their habitats to aquatic environments and evolved strategies for their rapid dispersal in these settings. By the mid-Cretaceous (90–100 Ma), angiosperms conquered higher latitudes in both hemispheres and expanded into various tropical to warm temperate (= subtropical) environments. Chloranthoids, laurels, and plane trees experienced their heyday. In the Late Cretaceous, core∗ and higher eudicots evolved rapidly, and nearly all extant angiosperm families appeared by the end of the Cretaceous. Angiosperm clades developed a physiology capable of overcoming drought conditions by the Cenomanian. However, their expansion and colonization of mesophytic upland habitats only took place in the Late Cretaceous. Seasonally dry habitats, such as savannas, were inhabited by angiosperms in the Late Cretaceous, with the first evidence of graminoids.
Fig. 21. A. 3D model of the Omorgus gigas (Harold, 1872) beetle after a quick segmentation, inclu... more Fig. 21. A. 3D model of the Omorgus gigas (Harold, 1872) beetle after a quick segmentation, including the metal artefact. B. 3D model of the same specimen after manual removal of the pin in the Dragonfly software (http://www.theobjects.com/dragonfly/). Clicking on the image opens the 3D model. Photo courtesy of the Royal Belgian Institute of Natural Sciences (RBINS) / DIGIT-3 Belspo, CC-BY-NC-ND Jonathan Brecko.
Computed tomography provides 3D information of inner structures of investigated objects. The obta... more Computed tomography provides 3D information of inner structures of investigated objects. The obtained information is, however, strongly dependent on the used radiation type. It is known that as X-rays interact with electron cloud and neutrons with atomic nucleus, the obtained data often provide different contrast of sample structures. In this work we present a set of comparative radiographic and CT measurements of rare fossil plant samples using X-rays and thermal neutrons. The X-ray measurements were performed using large area photon counting detectors Timepix at IEAP CTU in Prague and Perkin Elmer flat-panel detector at Center of Excellence Telc. The neutron CT measurement was carried out at Paul Scherrer Institute using BOA beam-line. Furthermore, neutron radiography of fossil samples, provided by National Museum, were performed using a large-area Timepix detector with a neutron-sensitive converting 6LiF layer at Research Centre Rez, Czech Republic. The obtained results show different capabilities of both imaging approaches. While X-ray micro-CT provides very high resolution and enables visualization of fine cracks or small cavities in the samples neutron imaging provides high contrast of morphological structures of fossil plant samples, where X-ray imaging provides insufficient contrast.
Numerous data based on extant vegetation reveal global patterns of relationships between function... more Numerous data based on extant vegetation reveal global patterns of relationships between functional leaf traits and climate. Leaf life span (LLS), i.e. evergreen vs. deciduous leaves, represents a central parameter linking functional traits related to the global leaf economics spectrum. Paleogene climate transitions are therefore expected to be reflected by functional leaf traits and leaf economics. In this study, fossil floras from six sites in Central Europe dating back to the Paleocene, Late Eocene, Early and Late Oligocene are studied, addressing the following questions: 1) How does leaf economics and LLS change through the Paleogene? 2) How do various functional leaf traits change through the Paleogene, and how do they relate to leaf economics? 3) Are changes in leaf functional traits consistent with climate reconstructions from proxy data? As a proxy for LLS change, leaf mass per area (LM A) was determined indirectly. The results show the Late Eocene site to stand out from all other sites, by tending towards lower leaf size/width, higher leaf mass per area (LM A), a tendency towards untoothed leaf margins, a high frequency of looped secondary veins, an almost complete absence of lobed leaves, and a low proportion of toothed pinnate leaves with non-looped secondaries. The LM A peak at the Eocene site is caused by untoothed leaf
Sborník Národního muzea v Praze. Řada B, Přírodní vědy, Dec 20, 2014
A new fossil eusporangiate fern Marattiopsis vodrazkae J. Kvaček, sp. nov. has been recovered fro... more A new fossil eusporangiate fern Marattiopsis vodrazkae J. Kvaček, sp. nov. has been recovered from the Hidden Lake Formation, the Campanian of James Ross Island, Antarctica. Its fertile and sterile pinnules are described and compared to the other species of the fossil genus Marattiopsis Schimper and the living genera Marattia, Ptisana and Eupodium (Marattiaceae). In contrast to the other species of the genus Marattiopsis, M. vodrazkae is characterised by stalked synangia, a smaller number of sporangia per synangium, generally small sized pinnules, and the absence of venuli recurrentes. It shows a mosaic of characters present in the living Marattiaceae: it shares stalked sporangia with the genus Eupodium and some species of Marattia and exhibits a suture (an abscission scar at pinnule bases), a character typical for the genus Ptisana. Additionally, M. vodrazkae provides important palaeoenvironmental signals for climate reconstructions, arguing for warm (paratropical to warm-temperate) and humid climatic conditions on the Antarctic Peninsula and adjacent volcanic islands during the Campanian.
Palaeobiodiversity and Palaeoenvironments, Dec 10, 2023
A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of ... more A new find of terrestrial plant Equisetites cf. lyellii is reported from the Early Cretaceous of Slovakia. It comes from the Mráznica Formation of the Rajec Basin in Fatricum, Zbyňov locality, Rajecké Teplice (Žilina district). The presence of a 53 mm long horsetail axis provides good evidence of terrestrial environments during sedimentation of the studied strata. According to our interpretation, such a plant strongly indicates a moist to wet habitat (even swampy environments) on the presumed dryland from where it was transported. This dryland could represent an isolated unknown small island(s) in the vicinity, or the Vindelician-Bohemian Massif that was active as a dryland for the entire period of time from the Triassic through the Late Cretaceous. However, the exact palaeogeographic position of the Fatricum during the Mesozoic in relation to the Vindelician Landmass is not entirely clear, and such an interpretation needs a bit of caution.
Review of Palaeobotany and Palynology, Nov 1, 2020
Three types of charcoalified fossil homoxylous woods are described from the Upper Cretaceous of t... more Three types of charcoalified fossil homoxylous woods are described from the Upper Cretaceous of the Bohemian Cretaceous Basin: Podocarpoxylon sp.,?Podocarpoxylon vel Taxodioxylon sp. and Protocupressinoxylon sp. They come from the uppermost part of the Peruc-Korycany Formation, which is mid-Cenomanian in age. Podocarpoxylon sp. shows distinct growth rings, uniseriate rays of medium height, 1-2 podocarpoid cross-field pits, and abietinean pitting on radial tracheid walls. Wood of ?Podocarpoxylon vel Taxodioxylon sp. differs in its indistinct growth rings, its rays which are uniseriate with medium height to multiseriate with horizontal resin duct, 1-2 podocarpoid cross-field pits per field, and mixed type of pitting on its radial tracheid walls. Protocupressinoxylon sp. also displays indistinct growth rings, and its rays are either uniseriate of medium height or multiseriate with horizontal resin ducts, but it has 1, occasionally 2-3 cupressoid cross-field pits per field, and abietinean to mixed pitting on radial tracheid walls. One of the three woods shows wood with growth rings, suggesting seasonally dry climate. The composition of the wood assemblage and its comparison with plant megafossils, sporomorphs and sedimentology suggest that there are two paleoenvironments in Unit 5 of the Peruc-Korycany Formation in the Pecínov quarry: a swampy coniferous forest in the coastal lowlands, and a mesophytic forest in the uplands.
Review of Palaeobotany and Palynology, Dec 1, 2021
Abstract A new cheirolepidiaceous conifer Watsoniocladus cunhae sp. nov. J.Kvacek et M.M.Mendes i... more Abstract A new cheirolepidiaceous conifer Watsoniocladus cunhae sp. nov. J.Kvacek et M.M.Mendes is described from the Early Cretaceous of Catefica in the Lusitanian Basin, Estremadura region, western Portugal. The new species Watsoniocladus cunhae has been established based on sterile twigs showing decussately arranged s-shaped leaves equipped with stomata surrounded by papillae and arranged in short rows. The new species is compared to all already-published species assigned to Watsoniocladus. Additionally, based on the newly observed morphological features in the Portuguese material (cuticle characters), we transfer two species from Cupressinocladus (Cupressaceae) to Watsoniocladus (Cheirolepidiaceae): Watsoniocladus itieri (Saporta) comb. nov. from the late Kimmeridgian of southern Jura (France) and Watsoniocladus crassirameus (Zheng Y.Cao) comb. nov. from the Early Cretaceous of China.
The Late Cretaceous flora of the Klikov Formation (Upper Turonian-Santonian) in South Bohemia com... more The Late Cretaceous flora of the Klikov Formation (Upper Turonian-Santonian) in South Bohemia comprises 110 species representing pteridophytes, ferns, conifers, angiosperms, macro and mesofossils. Palaeoclimatic analysis of the Klikov Formation Flora using methods of Leaf Margin Analysis, Climate Leaf Analysis Multivariate Program (CLAMP) and the Nearest Living Relative allows us to conclude that this flora experienced a seasonally dry subtropical climate. Mean annual temperature is predicted to have been approximately 15°C. Numerous charcoalified fossils strongly suggest frequent fires typical of a seasonally dry climate.
Araucarian pollen cones Rabagostrobus hispanicus gen. et sp. nov. and their associated foliage Br... more Araucarian pollen cones Rabagostrobus hispanicus gen. et sp. nov. and their associated foliage Brachyphyllum obesum Heer are described from Lower Cretaceous (Albian) strata of northern Spain. Male cones consist of helically arranged microsporophylls bearing 5-8 elongate pollen sacs with in situ inaperturate Araucariacites-type pollen. The new taxon is compared to material described previously from the Early Cretaceous of North and South Americas. Sterile twigs of B. obesum bear helically arranged leaves with wrinkled margins. Its cuticle has files of predominantly transversely oriented stomata. Both twigs and pollen cones occur as inclusions in amber from the Peñacerrada 1 outcrop (Alava Province), and as compressions are recorded from the amber-bearing strata sediments of the R abago/El Soplao outcrop. Inclusions of araucariacean plant remains and the co-occurrence of amber and male cone and twig compressions suggest that the amber in these two localities, or at least some of it, was produced by araucariacean plants.
Springer Textbooks in Earth Sciences, Geography and Environment, 2020
Flowering plants, the angiosperms, are the most diverse group of plants on our planet. Today, the... more Flowering plants, the angiosperms, are the most diverse group of plants on our planet. Today, they dominate most vegetation types, but their origen continues to remain a mystery. However, we continue to gain knowledge about their early evolution and history. It seems increasingly probable that their origen is associated with climatic and environmental changes in tropical areas and was coeval with the breakup of the supercontinent Gondwana. The first angiosperms appeared in the fossil record about 135 million years ago based on the occurrence of their rare pollen grains in fossil assemblages of North Gondwana and southwest Europe. Their evolution may be associated with climate perturbation and an overall change in wetland to mesophytic habitats, as this group is adapted to tolerate a seasonally dry climate. Soon after the first early angiosperms in the late Valanginian, higher angiosperms, the eudicots, are part of the fossil record of Africa. These initial flowering plants had small inconspicuous flowers and small fruits, and were most probably of small growth stature, likely herbs and shrubs. After angiosperms colonized mineral soils across the landscape, they expanded their habitats to aquatic environments and evolved strategies for their rapid dispersal in these settings. By the mid-Cretaceous (90–100 Ma), angiosperms conquered higher latitudes in both hemispheres and expanded into various tropical to warm temperate (= subtropical) environments. Chloranthoids, laurels, and plane trees experienced their heyday. In the Late Cretaceous, core∗ and higher eudicots evolved rapidly, and nearly all extant angiosperm families appeared by the end of the Cretaceous. Angiosperm clades developed a physiology capable of overcoming drought conditions by the Cenomanian. However, their expansion and colonization of mesophytic upland habitats only took place in the Late Cretaceous. Seasonally dry habitats, such as savannas, were inhabited by angiosperms in the Late Cretaceous, with the first evidence of graminoids.
Fig. 21. A. 3D model of the Omorgus gigas (Harold, 1872) beetle after a quick segmentation, inclu... more Fig. 21. A. 3D model of the Omorgus gigas (Harold, 1872) beetle after a quick segmentation, including the metal artefact. B. 3D model of the same specimen after manual removal of the pin in the Dragonfly software (http://www.theobjects.com/dragonfly/). Clicking on the image opens the 3D model. Photo courtesy of the Royal Belgian Institute of Natural Sciences (RBINS) / DIGIT-3 Belspo, CC-BY-NC-ND Jonathan Brecko.
Computed tomography provides 3D information of inner structures of investigated objects. The obta... more Computed tomography provides 3D information of inner structures of investigated objects. The obtained information is, however, strongly dependent on the used radiation type. It is known that as X-rays interact with electron cloud and neutrons with atomic nucleus, the obtained data often provide different contrast of sample structures. In this work we present a set of comparative radiographic and CT measurements of rare fossil plant samples using X-rays and thermal neutrons. The X-ray measurements were performed using large area photon counting detectors Timepix at IEAP CTU in Prague and Perkin Elmer flat-panel detector at Center of Excellence Telc. The neutron CT measurement was carried out at Paul Scherrer Institute using BOA beam-line. Furthermore, neutron radiography of fossil samples, provided by National Museum, were performed using a large-area Timepix detector with a neutron-sensitive converting 6LiF layer at Research Centre Rez, Czech Republic. The obtained results show different capabilities of both imaging approaches. While X-ray micro-CT provides very high resolution and enables visualization of fine cracks or small cavities in the samples neutron imaging provides high contrast of morphological structures of fossil plant samples, where X-ray imaging provides insufficient contrast.
Numerous data based on extant vegetation reveal global patterns of relationships between function... more Numerous data based on extant vegetation reveal global patterns of relationships between functional leaf traits and climate. Leaf life span (LLS), i.e. evergreen vs. deciduous leaves, represents a central parameter linking functional traits related to the global leaf economics spectrum. Paleogene climate transitions are therefore expected to be reflected by functional leaf traits and leaf economics. In this study, fossil floras from six sites in Central Europe dating back to the Paleocene, Late Eocene, Early and Late Oligocene are studied, addressing the following questions: 1) How does leaf economics and LLS change through the Paleogene? 2) How do various functional leaf traits change through the Paleogene, and how do they relate to leaf economics? 3) Are changes in leaf functional traits consistent with climate reconstructions from proxy data? As a proxy for LLS change, leaf mass per area (LM A) was determined indirectly. The results show the Late Eocene site to stand out from all other sites, by tending towards lower leaf size/width, higher leaf mass per area (LM A), a tendency towards untoothed leaf margins, a high frequency of looped secondary veins, an almost complete absence of lobed leaves, and a low proportion of toothed pinnate leaves with non-looped secondaries. The LM A peak at the Eocene site is caused by untoothed leaf
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