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A late Wenlock flora from Co. Tipperary, Ireland 总被引:1,自引:0,他引:1
D. EDWARDS F.L.S. J. FEEHAN D. G. SMITH 《Botanical journal of the Linnean Society. Linnean Society of London》1983,86(1-2):19-36
An assemblage of macroplants preserved as highly coalified compressions which lack anatomy is described from a Wenlock locality in County Tipperary, Ireland. Most of the fertile specimens are assigned to Cooksonia Lang. The taxonomic status of this genus is discussed. Some poorly preserved palynomorphs, including miospores, acritarchs, chitinozoans and a variety of tubes, have been isolated from associated sediments, but the age of the flora is based on graptolites. Sedimentological and palaeontological studies of the region are summarized. They provide little direct evidence for the habitats of the plants which are considered to have been terrestrial. The relevance of this flora to the current debate on the colonization of the land is evaluated and it is concluded that these plants provide the earliest record of erect fertile land plants of possible pteridophyte affinity. 相似文献
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D. EDWARDS F.L.S. U. FANNING K. L. DAVIES L. AXE J. B. RICHARDSON 《Botanical journal of the Linnean Society. Linnean Society of London》1995,117(4):233-254
Reniform sporangia, comprising two equal valves and containing retusoid spores, recovered from Lower Old Red Sandstone strata of Devonian age ( micrornatus-newportensis Spore Biozone: lower Gedinnian lower Lochkovian) on North Brown Clee Hill in the Welsh Borderland are placed in Resilitheca salopensis gen. et sp. nov. Conventional compression fossils from Targrove, Ludlow of fertile axes showing isotomous branching with limited overtopping are considered conspecific because the terminal reniform sporangia contain the same spores. Spore ultrastructure is described using scanning and transmission electron microscopy. Sections show faint traces of lamellae. Particles associated with spores and sporangium wall are compared with the globules of pteridophytes and Ubisch bodies of angiosperms, and related to the development of the sporangium. The new plants are compared with Cooksonia caledonica Edwards known only from impressions, and with Renalia Gensel showing far more pronounced pseudomonopodial branching. 相似文献
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D. EDWARDS U. FANNING K. L. DAVIES L. AXE J. B. RICHARDSON 《Botanical journal of the Linnean Society. Linnean Society of London》1995,117(3):233-254
Reniform sporangia, comprising two equal valves and containing retusoid spores, recovered from Lower Old Red Sandstone strata of Devonian age (micrornatus-newportensis Spore Biozone: lower Gedinnian lower Lochkovian) on North Brown Clee Hill in the Welsh Borderland are placed in Resilitheca salopensis gen. et sp. nov. Conventional compression fossils from Targrove, Ludlow of fertile axes showing isotomous branching with limited overtopping are considered conspecific because the terminal reniform sporangia contain the same spores. Spore ultrastructure is described using scanning and transmission electron microscopy. Sections show faint traces of lamellae. Particles associated with spores and sporangium wall are compared with the globules of pteridophytes and Ubisch bodies of angiosperms, and related to the development of the sporangium. The new plants are compared with Cooksonia caledonica Edwards known only from impressions, and with Renalia Gensel showing far more pronounced pseudomonopodial branching. 相似文献
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R. J. RAYNER 《Botanical journal of the Linnean Society. Linnean Society of London》1988,97(2):229-237
Early putative vascular plants from the type locality of Dutoitea maraisia , in Lower Devonian sediments from South Africa are described. The plants, assigned to three species of Dutoitea , are similar in morphology to Cooksonia from the northern hemisphere. The taxonomic status of the plants is discussed and it is suggested that Cooksonia is a later synonym of Dutoitea . 相似文献
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