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William A. Dimichele - One of the best experts on this subject based on the ideXlab platform.
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dryland vegetation from the middle pennsylvanian of indiana illinois basin the dryland biome in glacioeustatic paleobiogeographic and paleoecologic context
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:A macrofloral assemblage dominated by elements of the Euramerican dryland biome is described from the Brazil Formation in Clay County, Indiana (Illinois Basin). Fossils were recovered from a thin heterolithic unit between a shallow-marine bed and the paleosol beneath the Minshall Coal, a Middle Pennsylvanian succession deposited near the Atokan-Desmoinesian and Bolsovian-Asturian boundaries. Sedimentological indicators imply accumulation under a seasonal climate, including interbedded siltstone and sandstone deposited during flashfloods, intraclasts eroded from local sources, and charcoal produced by wildfires. The macrofloral assemblage is consistent with a dryland setting, being dominated by large, coriaceous gymnosperm leaves with mesic to xeric traits, including Cordaites spp. indet., Lesleya sp. indet., and Taeniopteris sp. cf. T. multinervia. Sphenopsids and ferns typical of the wetland biome are rare. In contrast, the microfloral assemblage is dominated by fern spores, with lesser lycopsid spores and cordaitalean pollen. The succession indicates that the dryland biome predominated during late regression, prior to the onset of perhumid conditions that resulted in peat accumulation at late lowstand. However, the abundance of palynomorphs from wetland vegetation implies gradual fragmentation of the prevailing dryland flora and replacement by the wetland biome in the transition to glacial maximum. The taphonomic and paleobiogeographic context confirms that floras adapted to seasonal moisture deficit periodically dispersed into tropical lowlands, rather than being transported from ‘extrabasinal’ or ‘upland’ environments. The precocious occurrence of Taeniopteris, more typical of Late Pennsylvanian and Permian floras, may be the earliest record of the fossil-genus, and exemplifies the association of derived plant taxa with dryland habitats. The predominance of broad-leaved gymnosperms with mesic to xeric characters suggests that dryland communities contained more slow-growing and long-lived plants than contemporaneous wetland floras.
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a middle pennsylvanian macrofloral assemblage from wetland deposits in indiana illinois basin a taxonomic contribution with biostratigraphic paleobiogeographic and paleoecologic implications
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:Taxonomic analysis is provided for a Middle Pennsylvanian macrofloral assemblage collected from clastic wetland deposits in Clay County, Indiana, on the eastern margin of the Illinois Basin. Adpressed plant fossils were recovered from four distinct beds in the lowermost Staunton Formation, positioned above the Minshall Coal (uppermost Brazil Formation), part of a succession deposited near the Atokan-Desmoinesian boundary. The assemblage of 22 fossil-taxa is dominated by pteridosperms (including Neuropteris flexuosa, Macroneuropteris scheuchzeri, Alethopteris densinervosa, Neuropteris ovata, Eusphenopteris neuropteroides, and Neuropteris missouriensis) with lesser cordaitaleans (Cordaites spp. indet.) and sphenopsids (particularly Sphenophyllum cuneifolium). Lycopsids are uncommon, and ferns are rare. In contrast, the microfloral assemblage from the Minshall Coal and overlying clastic units is dominated by lycopsid and tree fern spores. Comparisons with established biozonation schemes yield different ages depending on the regional biostratigraphic framework used: (1) latest Bolsovian (Radiizonates difformis Biozone, American microfloras); (2) latest Bolsovian or earliest Asturian (‘Neuropteris’ rarinervis Biozone, Appalachian Basin macrofloras); or (3) earliest Asturian (Linopteris obliqua Biozone, European macrofloras). The placement and correlation of the Bolsovian-Asturian and Atokan-Desmoinesian boundaries, which have traditionally been equated by palynology, are evaluated in the context of this discordance. Several revised stratigraphic scenarios are proposed for this interval in the Illinois Basin, which is being increasingly recognized as a time of significant environmental change throughout Euramerica. Homotaxial comparisons with European macrofloral assemblages indicate that, of the 18 biological taxa recorded, between 14 and 17 (78–94%) also are common in coeval wetland deposits in Europe. The similarities exemplify the spatial conservatism and low diversity of wetland plant communities over vast areas of tropical Euramerica, a manifestation of the intrinsically stressful conditions that characterize such habitats, and indicates that neither the Laurentian Shield nor the Appalachian-Variscan Mountains were an insurmountable barrier to plant dispersal during the Middle Pennsylvanian.
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AN UNUSUAL MIDDLE PERMIAN FLORA FROM THE BLAINE FORMATION (PEASE RIVER GROUP: LEONARDIAN-GUADALUPIAN SERIES) OF KING COUNTY, WEST TEXAS
2015Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting
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an unusual middle permian flora from the blaine formation pease river group leonardian guadalupian series of king county west texas
Journal of Paleontology, 2004Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:A new Middle Permian plant assemblage from South Ash Pasture in King County, Texas, may be the youngest and is certainly the most unusual flora known from the Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting.
Dan S. Chaney - One of the best experts on this subject based on the ideXlab platform.
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AN UNUSUAL MIDDLE PERMIAN FLORA FROM THE BLAINE FORMATION (PEASE RIVER GROUP: LEONARDIAN-GUADALUPIAN SERIES) OF KING COUNTY, WEST TEXAS
2015Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting
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an unusual middle permian flora from the blaine formation pease river group leonardian guadalupian series of king county west texas
Journal of Paleontology, 2004Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:A new Middle Permian plant assemblage from South Ash Pasture in King County, Texas, may be the youngest and is certainly the most unusual flora known from the Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting.
John W. Nelson - One of the best experts on this subject based on the ideXlab platform.
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dryland vegetation from the middle pennsylvanian of indiana illinois basin the dryland biome in glacioeustatic paleobiogeographic and paleoecologic context
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:A macrofloral assemblage dominated by elements of the Euramerican dryland biome is described from the Brazil Formation in Clay County, Indiana (Illinois Basin). Fossils were recovered from a thin heterolithic unit between a shallow-marine bed and the paleosol beneath the Minshall Coal, a Middle Pennsylvanian succession deposited near the Atokan-Desmoinesian and Bolsovian-Asturian boundaries. Sedimentological indicators imply accumulation under a seasonal climate, including interbedded siltstone and sandstone deposited during flashfloods, intraclasts eroded from local sources, and charcoal produced by wildfires. The macrofloral assemblage is consistent with a dryland setting, being dominated by large, coriaceous gymnosperm leaves with mesic to xeric traits, including Cordaites spp. indet., Lesleya sp. indet., and Taeniopteris sp. cf. T. multinervia. Sphenopsids and ferns typical of the wetland biome are rare. In contrast, the microfloral assemblage is dominated by fern spores, with lesser lycopsid spores and cordaitalean pollen. The succession indicates that the dryland biome predominated during late regression, prior to the onset of perhumid conditions that resulted in peat accumulation at late lowstand. However, the abundance of palynomorphs from wetland vegetation implies gradual fragmentation of the prevailing dryland flora and replacement by the wetland biome in the transition to glacial maximum. The taphonomic and paleobiogeographic context confirms that floras adapted to seasonal moisture deficit periodically dispersed into tropical lowlands, rather than being transported from ‘extrabasinal’ or ‘upland’ environments. The precocious occurrence of Taeniopteris, more typical of Late Pennsylvanian and Permian floras, may be the earliest record of the fossil-genus, and exemplifies the association of derived plant taxa with dryland habitats. The predominance of broad-leaved gymnosperms with mesic to xeric characters suggests that dryland communities contained more slow-growing and long-lived plants than contemporaneous wetland floras.
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a middle pennsylvanian macrofloral assemblage from wetland deposits in indiana illinois basin a taxonomic contribution with biostratigraphic paleobiogeographic and paleoecologic implications
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:Taxonomic analysis is provided for a Middle Pennsylvanian macrofloral assemblage collected from clastic wetland deposits in Clay County, Indiana, on the eastern margin of the Illinois Basin. Adpressed plant fossils were recovered from four distinct beds in the lowermost Staunton Formation, positioned above the Minshall Coal (uppermost Brazil Formation), part of a succession deposited near the Atokan-Desmoinesian boundary. The assemblage of 22 fossil-taxa is dominated by pteridosperms (including Neuropteris flexuosa, Macroneuropteris scheuchzeri, Alethopteris densinervosa, Neuropteris ovata, Eusphenopteris neuropteroides, and Neuropteris missouriensis) with lesser cordaitaleans (Cordaites spp. indet.) and sphenopsids (particularly Sphenophyllum cuneifolium). Lycopsids are uncommon, and ferns are rare. In contrast, the microfloral assemblage from the Minshall Coal and overlying clastic units is dominated by lycopsid and tree fern spores. Comparisons with established biozonation schemes yield different ages depending on the regional biostratigraphic framework used: (1) latest Bolsovian (Radiizonates difformis Biozone, American microfloras); (2) latest Bolsovian or earliest Asturian (‘Neuropteris’ rarinervis Biozone, Appalachian Basin macrofloras); or (3) earliest Asturian (Linopteris obliqua Biozone, European macrofloras). The placement and correlation of the Bolsovian-Asturian and Atokan-Desmoinesian boundaries, which have traditionally been equated by palynology, are evaluated in the context of this discordance. Several revised stratigraphic scenarios are proposed for this interval in the Illinois Basin, which is being increasingly recognized as a time of significant environmental change throughout Euramerica. Homotaxial comparisons with European macrofloral assemblages indicate that, of the 18 biological taxa recorded, between 14 and 17 (78–94%) also are common in coeval wetland deposits in Europe. The similarities exemplify the spatial conservatism and low diversity of wetland plant communities over vast areas of tropical Euramerica, a manifestation of the intrinsically stressful conditions that characterize such habitats, and indicates that neither the Laurentian Shield nor the Appalachian-Variscan Mountains were an insurmountable barrier to plant dispersal during the Middle Pennsylvanian.
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AN UNUSUAL MIDDLE PERMIAN FLORA FROM THE BLAINE FORMATION (PEASE RIVER GROUP: LEONARDIAN-GUADALUPIAN SERIES) OF KING COUNTY, WEST TEXAS
2015Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting
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an unusual middle permian flora from the blaine formation pease river group leonardian guadalupian series of king county west texas
Journal of Paleontology, 2004Co-Authors: William A. Dimichele, Robert W. Hook, John W. Nelson, Dan S. ChaneyAbstract:A new Middle Permian plant assemblage from South Ash Pasture in King County, Texas, may be the youngest and is certainly the most unusual flora known from the Permian of either West Texas or adjoining north-central Texas. Found serendipitously in the evaporite-rich upper Blaine Formation (Pease River Group, Guadalupian Series), the flora is of very low diversity despite intensive collecting efforts, and the affinities of nearly all taxa are enigmatic. The most common elements are parallel-veined leaves that resemble Cordaites but that could be isolated pinnules of a pinnate leaf. Gigantopterid foliage is present but not assignable to any known taxon. A single foliar conifer specimen is too incomplete for assignment. Numerous reproductive organs, however, and an abundance of axes may represent conifers. Conchostracans, palaeoniscoid fish scales, and small heteropolar coprolites also occur in the deposit, which originated as a small, claystone-dominated channel fill in a coastal plain setting.
Annette E. Götz - One of the best experts on this subject based on the ideXlab platform.
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Palynofacies as a tool for high-resolution palaeoenvironmental and palaeoclimatic reconstruction of Gondwanan post-glacial coal deposits: No. 2 Coal Seam, Witbank Coalfield (South Africa)
Palaeobiodiversity and Palaeoenvironments, 2017Co-Authors: Alexander Wheeler, Annette E. GötzAbstract:The early Permian movement of Gondwana away from the South Pole caused a major climatic change across the continent. The shift from a post-glacial Carboniferous flora to a temperate Permian flora is represented in the palynological record. Using palynofacies analysis, this climate transition can be studied at a high resolution, and the palaeoenvironment can be interpreted on a local scale. Core samples were studied from four localities of the Artinskian/Kungurian-aged No. 2 Coal Seam of the Witbank Coalfield. At some localities, the No. 2 Coal Seam is split into an Upper Coal Seam and a Lower Coal Seam by an intraseam parting, and samples were collected from both horizons as well as the parting. All samples were studied with respect to palynomorph composition and phytoclast content. The results suggest a swamp-dominated environment in the Lower Coal Seam, a river-dominated environment in the parting, and an environment which fluctuated locally from a lake-dominated to swamp-dominated in the Upper Coal Seam due to increased input of glacial meltwater from the hinterlands. The vegetation switched from a fern- and conifer-dominated flora in the Lower Coal Seam to a more diverse Glossopteris-Gangamopteris flora in the Upper Coal Seam. Cordaites appears to be limited to valleys on the northern edge of the swamplands in the Lower Coal Seam. A decrease in monosaccate pollen grains and an increase in bisaccate pollen grains are apparent in all sample sets and interpreted to indicate a transition from a cold to a fluctuating cool-temperate climate. This climate signal is well documented in palynofacies of the coal seam and thus a powerful correlation tool for high-resolution basin-wide and Gondwanan correlation.
Arden R Bashforth - One of the best experts on this subject based on the ideXlab platform.
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dryland vegetation from the middle pennsylvanian of indiana illinois basin the dryland biome in glacioeustatic paleobiogeographic and paleoecologic context
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:A macrofloral assemblage dominated by elements of the Euramerican dryland biome is described from the Brazil Formation in Clay County, Indiana (Illinois Basin). Fossils were recovered from a thin heterolithic unit between a shallow-marine bed and the paleosol beneath the Minshall Coal, a Middle Pennsylvanian succession deposited near the Atokan-Desmoinesian and Bolsovian-Asturian boundaries. Sedimentological indicators imply accumulation under a seasonal climate, including interbedded siltstone and sandstone deposited during flashfloods, intraclasts eroded from local sources, and charcoal produced by wildfires. The macrofloral assemblage is consistent with a dryland setting, being dominated by large, coriaceous gymnosperm leaves with mesic to xeric traits, including Cordaites spp. indet., Lesleya sp. indet., and Taeniopteris sp. cf. T. multinervia. Sphenopsids and ferns typical of the wetland biome are rare. In contrast, the microfloral assemblage is dominated by fern spores, with lesser lycopsid spores and cordaitalean pollen. The succession indicates that the dryland biome predominated during late regression, prior to the onset of perhumid conditions that resulted in peat accumulation at late lowstand. However, the abundance of palynomorphs from wetland vegetation implies gradual fragmentation of the prevailing dryland flora and replacement by the wetland biome in the transition to glacial maximum. The taphonomic and paleobiogeographic context confirms that floras adapted to seasonal moisture deficit periodically dispersed into tropical lowlands, rather than being transported from ‘extrabasinal’ or ‘upland’ environments. The precocious occurrence of Taeniopteris, more typical of Late Pennsylvanian and Permian floras, may be the earliest record of the fossil-genus, and exemplifies the association of derived plant taxa with dryland habitats. The predominance of broad-leaved gymnosperms with mesic to xeric characters suggests that dryland communities contained more slow-growing and long-lived plants than contemporaneous wetland floras.
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a middle pennsylvanian macrofloral assemblage from wetland deposits in indiana illinois basin a taxonomic contribution with biostratigraphic paleobiogeographic and paleoecologic implications
Journal of Paleontology, 2016Co-Authors: Arden R Bashforth, Cortland F Eble, William A. Dimichele, John W. NelsonAbstract:Taxonomic analysis is provided for a Middle Pennsylvanian macrofloral assemblage collected from clastic wetland deposits in Clay County, Indiana, on the eastern margin of the Illinois Basin. Adpressed plant fossils were recovered from four distinct beds in the lowermost Staunton Formation, positioned above the Minshall Coal (uppermost Brazil Formation), part of a succession deposited near the Atokan-Desmoinesian boundary. The assemblage of 22 fossil-taxa is dominated by pteridosperms (including Neuropteris flexuosa, Macroneuropteris scheuchzeri, Alethopteris densinervosa, Neuropteris ovata, Eusphenopteris neuropteroides, and Neuropteris missouriensis) with lesser cordaitaleans (Cordaites spp. indet.) and sphenopsids (particularly Sphenophyllum cuneifolium). Lycopsids are uncommon, and ferns are rare. In contrast, the microfloral assemblage from the Minshall Coal and overlying clastic units is dominated by lycopsid and tree fern spores. Comparisons with established biozonation schemes yield different ages depending on the regional biostratigraphic framework used: (1) latest Bolsovian (Radiizonates difformis Biozone, American microfloras); (2) latest Bolsovian or earliest Asturian (‘Neuropteris’ rarinervis Biozone, Appalachian Basin macrofloras); or (3) earliest Asturian (Linopteris obliqua Biozone, European macrofloras). The placement and correlation of the Bolsovian-Asturian and Atokan-Desmoinesian boundaries, which have traditionally been equated by palynology, are evaluated in the context of this discordance. Several revised stratigraphic scenarios are proposed for this interval in the Illinois Basin, which is being increasingly recognized as a time of significant environmental change throughout Euramerica. Homotaxial comparisons with European macrofloral assemblages indicate that, of the 18 biological taxa recorded, between 14 and 17 (78–94%) also are common in coeval wetland deposits in Europe. The similarities exemplify the spatial conservatism and low diversity of wetland plant communities over vast areas of tropical Euramerica, a manifestation of the intrinsically stressful conditions that characterize such habitats, and indicates that neither the Laurentian Shield nor the Appalachian-Variscan Mountains were an insurmountable barrier to plant dispersal during the Middle Pennsylvanian.
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a middle pennsylvanian bolsovian peat forming forest preserved in situ in volcanic ash of the whetstone horizon in the radnice basin czech republic
Review of Palaeobotany and Palynology, 2009Co-Authors: Stanislav Oplustil, Arden R Bashforth, Zbyněk Simůnek, Milan Libertin, Josef Psenicka, Jana Drabkova, Jiřina DaskovaAbstract:Abstract The precursory mire of the Middle Pennsylvanian (Bolsovian) Lower Radnice Coal was buried in situ by volcanic ash, preserving the taxonomic composition, spatial distribution, vertical stratification, and synecology of this peat-forming ecosystem in extraordinary detail. Plant fossil remains represent the pre-eruption vegetation of the swamp, which resulted from accumulation of peat in a high-ash, planar (rheotrophic) mire situated in a narrow palaeovalley containing an active fluvial system. A tuff bed (the Bělka) at the base of the volcaniclastic Whetstone Horizon was exposed in two contiguous excavations over an area of 50 m 2 in the Radnice Basin of western Bohemia, Czech Republic. Twenty-seven morphotaxa were identified, representing 20 whole-plant species with a wide variety of growth forms. The canopy of the peat-forming community was dominated by Cordaites borassifolius trees together with the arborescent lycopsid “ Lepidodendron ” (= Paralycopodites ), whereas Lepidophloios cf. acerosus was subdominant. Evidence suggests that the laterally extensive “crowns” of these arborescent lycopsids would have overlapped during the final phase of their life cycles, but differences in the height of tree species resulted in a complex and vertically variable canopy interrupted by randomly distributed gaps. The understorey was dominated by medullosan pteridosperms and marattialean tree ferns, whereas zygopterid ferns and sphenophylls comprised the bulk of the ground cover. In comparison with the canopy, understorey and ground cover species were less abundant and patchier in distribution, with almost complete absence beneath the deep shade of C. borassifolius trees. Lianas that entwined arborescent trees were an important component of the peat-forming forest. Three lyginopterid pteridosperm species along with a sphenophyll had a lianescent habit based on their close association with upright or prone lycopsid trunks and “canopy” branches. Species richness in the swamp superficially appears low. However, considering the small area of excavation, along with the higher diversity known from the same tuff bed in the adjacent, former opencast Ovcin Mine, it appears that species richness in the forest was comparable to some of the less diverse Westphalian peat-forming swamps in the U.S.A. The Lower Radnice mire vegetation was compositionally homogeneous, but had a heterogeneous distribution with patchiness occurring at a very fine scale. The preserved plant assemblage most resembles mires dominated by medullosan pteridosperms and Paralycopodites described from upper Westphalian coal balls in the U.S.A., which were characterised by high diversity in all storeys and involved plants centred in high-ash peat-forming swamps.
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functional groups and elemental analyses of cuticular morphotypes of Cordaites principalis germar geinitz carboniferous maritimes basin canada
International Journal of Coal Geology, 2000Co-Authors: Erwin L Zodrow, Maria Mastalerz, William H Orem, Zbynek Simunek, Arden R BashforthAbstract:Well-preserved cuticles were isolated from Cordaites principalis Germar Geinitz leaf compressions, i.e., foliage from extinct gymnosperm trees Coniferophyta: Order Cordaitales. The specimens were collected from the Sydney, Stellarton and Bay St. George subbasins of the once extensive Carboniferous Maritimes Basin of Atlantic Canada. Fourier transformation . of infrared spectra FTIR and elemental analyses indicate that the ca. 300-306-million-year-old fossil cuticles share many of the functional groups observed in modern cuticles. The similarities of the functional groups in each of the three cuticular . morphotypes studied support the inclusion into a single cordaite-leaf taxon, i.e., C. principalis Germar , confirming previous morphological investigations. Vitrinite reflectance measurements on coal seams in close proximity to the fossil-bearing sediments reveal that the Bay St. George sample site has the lowest thermal maturity, whereas the sites in Sydney and Stellarton are more mature. IR absorption and elemental analyses of the cordaite compressions corroborate this trend, which suggests that the coalified mesophyll in the leaves follows a maturation path similar to that of vitrinite. Comparison of functional groups of the cordaite cuticles with those from certain pteridosperms previously studied from the y1. Sydney Subbasin shows that in the cordaite cuticles highly conjugated C-O 1632 cm bands dominate over carbonyl stretch that characterizes the pteridosperm cuticles. The differences demonstrate the potential of chemotaxonomy as a valuable tool to assist distinguishing between Carboniferous plant-fossil groups. Published by Elsevier Science B.V.
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new cuticular morphotypes of Cordaites principalis from the canadian carboniferous maritimes basin
Botany, 2000Co-Authors: Erwin L Zodrow, Zbynek Simunek, Arden R BashforthAbstract:Fossil cuticles were extracted from leaves attributed to Cordaites principalis (Germar) Geinitz (Cordaitales) that were collected from Upper Carboniferous strata in Nova Scotia (Sydney and Stellarton sub-basins) and in Newfoundland (Bay St. George sub-basin). The quality of the cuticular preservation is directly related to the thermal maturity and the grain size and angularity of sediments entombing the fossil leaves. Detailed transmitted light and scanning electron microscopy of the cuticles revealed that five distinct cuticular morphotypes could be recognized, demonstrating the variability in epidermal morphology of leaves belonging to one taxon. Two morphotypes show dissimilar and discrete epidermal characteristics, whereas three morphotypes form, more or less, a morphological continuum. Comparison with cuticles from Euramerican and Angaran floral provinces suggests that only one morphotype is in common with cuticles described from Europe, while four morphotypes are new for the Carboniferous.Key words:...