2002 Fiscal Year Final Research Report Summary
The origin of a Mesozoic plant Bennettitales, and extinction
| Project/Area Number |
13640474
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Institute of Natural History |
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Principal Investigator |
OHANA Tamiko Institute of Natural History, Researcher, 研究員 (60231205)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Bennetticarpus / Hokkaido / Mesozoic / Ryoseki-type flora / Yezo Group / 領石型植物群 |
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| Research Abstract |
The bennettitales is classified into many genus according to the external form. In the Eastern Asia, bennettilates were grow in both the Tetori-type flora and the RyosekPtype flora. However, in these cuticle structures, the influence of the environments of the growth area has appeared. The bennettitales of the same species are not found from both floras. Therefore, the origin of a bennettitales is considered before establishing the both floras (before Early Jurassic).
Modern plants is classified according to the structure of the reproductive organ. Although it is the same also in a fossil plant, though unfortunately, the fossil plant is fragmentary and it is rare that the parts of all plants find together. Therefore, there is Little information acquired and it must be 'judged from few of the information.
Consequently, it is find out that bennettitalean reproductive organ is similar to that of some Palaeozoic primitive seed ferns. This has suggested a possibility that bennettitales and seed fern have a common ancestor. However, the thing with the feature of reproductive organ that bennettitales and a modern plant is not found yet.
The early angiosperm appeared in the Early Cretaceous in the Eastern Eurasia. However the direct relation between bennettitales and angiosperm is not understood yet, it is expected that the plant which become the ancestor of angiosperm out of primitive bennettitales has been produced.
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