石灰藻類の系統発生について (予報)
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概要
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Interest in the study of calcareous algae increased rather slowly from the latter half of the 19th century until the beginning of this century. Then, during the last decade, the study of these algae was greatly promoted by the efforts of several eminent paleontologists, namely J. V. Pia, J. Harlan Johnson, V. P. Maslov, K. B. Korde, H. Yabe and others. Almost all the works of these scientists, however, are descriptions and illustrations of the algal genera and species, no phylogenetic or evolutionary works were published except for the two following papers. J. V. Pia : Einige Ergebnisse neuer Untersuchungen uber die Geschichte der Siphoneae verticillatae in 1922. Erwin Kamptner : Uber das System und die Stammgeschichte der Dasycladaceen (Siphoneae verticillatae) in 1958. These two papers treated only the phylogenetical problems of the Dasycladaceae and not on those of the other algal families. In the present paper, the writer discusses tentatively the phylogenetic relationships among almost all of the Mesozoic and Paleozoic genera of Codiaceae, Spongiostroma, Porostroma and Rhodophyceae, in addition to the Dasycladacean genera. Though the relationships among these genera will be seen clearly in the annexed tables, several interesting problems from the phylogenetical point of view are described and discussed in this paper. The writer emphasizes the following three ideas. The writer discusses the inorganic origin of the genera Collenia, Cryptozoon, Gymnosolen, Codonophycus and other allied structures. These so-called algal genera show no real algal filaments in their thin sections, and no characteristic morphological appearances which deserve generic and specific names. Moreover, these structures show no definite stratigraphical significance. In 1906 Gurich established five genera, Aphralysia, Chondrostroma, Malacostroma, Pycnostroma and Aphrostoma, at the same time he created the genus Spongiostroma. Unfortunately, the writer could find no definite generic morphological differences among the six in Gurich's descriptions and illustrations. In 1940 Johnson established several genera, such as Calyptophycus, Artophycus, Shermanophycus, Stylophycus, Leptophycus and Gouldina. The general features of these so-called algal genera show nearly the same features as the Collenia group does : they form rounded colonies consisting of thin irregular concentric layers and an outer portion of irregular mammillae. The present writer, therefore, has some doubts that these genera can be distinguished clearly from each other.
- 東北大学の論文
- 1960-05-05