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Umkomasia Macleanii
''Umkomasia macleanii'' is an ovulate structure of a seed fern (Pteridospermatophyta The term Pteridospermatophyta (or "seed ferns" or "Pteridospermatopsida") is a polyphyletic group of extinct seed-bearing plants (spermatophytes). The earliest fossil evidence for plants of this type is the genus ''Elkinsia'' of the late Devonia ... and the nominate genus of Family Umkomasiaceae. It was first described by Hamshaw Thomas from the Umkomaas locality of South Africa. Description The ovulate structures of ''Umkomasia macleanii'' differ from other species of '' Umkomasia'' in small size, and limited geographic distribution. Whole plant reconstructions ''Umkomasia macleanii'' may have been produced by the same plant as '' Pteruchus africanus'' (pollen organs) and '' Dicroidium odontopteroides'' (leaves), based on cuticular similarities between these leaves and reproductive structures at the Umkomaas locality of South Africa. References Triassic plants Pteridospermatop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteridospermatophyta
The term Pteridospermatophyta (or "seed ferns" or "Pteridospermatopsida") is a polyphyletic group of extinct seed-bearing plants (spermatophytes). The earliest fossil evidence for plants of this type is the genus ''Elkinsia'' of the late Devonian age. They flourished particularly during the Carboniferous and Permian periods. Pteridosperms declined during the Mesozoic Era and had mostly disappeared by the end of the Cretaceous Period, though some pteridosperm-like plants seem to have survived into Eocene times, based on fossil finds in Tasmania. With regard to the enduring utility of this division, many palaeobotanists still use the pteridosperm grouping in an informal sense to refer to the seed plants that are not angiosperms, coniferoids (conifers or cordaites), ginkgophytes or cycadophytes (cycads or bennettites). This is particularly useful for extinct seed plant groups whose systematic relationships remain speculative, as they can be classified as pteridosperms with no vali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umkomasia Macleani Reconstruction
''Umkomasia'' is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. He recognized on the basis of cuticular similarities that the same plant produced pollen organs ''Pteruchus'' and the leaves ''Dicroidium''. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with ''Umkomasia'' being restricted to the Triassic. Description Umkomasia has helmet like cupules around ovules born in complex large branching structures. Whole plant associations *''Umkomasia feistmantelii'' from the Early Triassic of Australia may have been produced by the same plant as ''Pteruchus barrealensis'' (pollen organs) and ''Dicroidium zuberi'' (leaves) *''Umkomasia macleanii'' from the Late Triassic of South Africa may have been produced by the same p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umkomasia
''Umkomasia'' is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. He recognized on the basis of cuticular similarities that the same plant produced pollen organs ''Pteruchus'' and the leaves ''Dicroidium''. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with ''Umkomasia'' being restricted to the Triassic. Description Umkomasia has helmet like cupules around ovules born in complex large branching structures. Whole plant associations *'' Umkomasia feistmantelii'' from the Early Triassic of Australia may have been produced by the same plant as '' Pteruchus barrealensis'' (pollen organs) and ''Dicroidium zuberi'' (leaves) *''Umkomasia macleanii'' from the Late Triassic of South Africa may have been produced by the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteruchus Africanus
''Pteruchus africanus'' is a pollen organ of a seed fern (Pteridospermatophyta). It was first described by Hamshaw Thomas from the Umkomaas locality of South Africa. Description The pollen organs ''Pteruchus africanus'' differ from other species of ''Pteruchus'' in small size, and equant blade supporting the pollen sacs. Whole plant reconstructions ''Pteruchus africanus'' may have been produced by the same plant as '' Umkomasia macleanii'' (ovulate organs) and ''Dicroidium odontopteroides ''Dicroidium odontopteroides'' was a common and widespread species of ''Dicroidium'' known from South Africa, Australia, New Zealand, South America and Antarctica. The species was first discovered in Triassic sediments of Tasmania and described ...'' (leaves), based on cuticular similarities between these leaves and reproductive structures at the Umkomaas locality of South Africa. References Triassic plants Pteridospermatophyta {{triassic-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicroidium Odontopteroides
''Dicroidium odontopteroides'' was a common and widespread species of ''Dicroidium'' known from South Africa, Australia, New Zealand, South America and Antarctica. The species was first discovered in Triassic sediments of Tasmania and described by the palaeontologist John Morris in 1845. Description The leaves of ''Dicroidium odontopteroides'' differ from other species of ''Dicroidium ''Dicroidium'' is an extinct genus of fork-leaved seed ferns that were widely distributed over Gondwana during the Triassic (). Their fossils are known from South Africa, the Arabian Peninsula, Australia, New Zealand, South America, Madagascar ...'' in being unipinnate and having short rounded pinnae. Whole plant reconstructions ''Dicroidium odontopteroides'' may have been produced by the same plant as '' Umkomasia macleanii'' (ovulate structures) and '' Pteruchus africanus'' (pollen organs), based on cuticular similarities between these leaves and reproductive structures at the Umkomaas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic Plants
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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