Studies on the Genus Nephrolepidina in Japan

The Nephrolepidina assemblages from the Early Miocene formations in Japan were studied giving full account to their systematics, stratigraphic distribution, and paleozoogeography. The Nephrolepidina samples from Italy, Greece and Australia were studied in comparison with the Japanese Nephrolepidina. For the evaluation of their classification and evolution, the external and internal morphology of the shell was studied for interpretation of the species variation, the growth of the organism, and based upon these parameters, the specimens from each recognized population were investigated biometrically by statistical treatment. Three form groups were recognized in the phylogenetic development of the embryonic acceleration of the local Nephrolepidina populations ascertained in the respective areas studied. Based upon these groups the Early Miocene Series in Japan could be subdivided. Among the nephrolepidinas studied the following series of phylogenetic trends from the Chattian to Burdigalian, were recognized : Nephrolepidina. morgani-Nephrolepidina angulosa, Nephrolepidina tournoueri-Nephrolepidina howchini and Nephrolepidina tournoueri-Nephrolepidina japonica. Also included in this paper are the descriptions, geologic and geographic occurrences and phylogenetic trends of other larger Foraminifera genera as Miogypsina, Miolepidocyclina, Cycloclypeus, Homotrema and Gypsina which accompany Nephrolepidina in Japan

Geology of the Tomioka Area, Gunma Prefecture, with a note on "Lepidocyclina" from the Abuta Limestone Member

The Tertiary System distributed in the area extending from Shimonita-machi to the west of Takasaki City, Gunma Prefecture was studied with the purpose to make a biostratigraphical classification of the different lithological units based upon the Foraminifera (planktonic and benthonic). Emphasis was given to the interpretation of the geostructure, sedimentary environment of the fossiliferous Tertiary strata, geological ages of the stratigraphic units, correlation with other areas and to make a paleontological study on Nephrolepidina from the present area. Descriptions are given to each of the formations recognized in the field, preserved specimens of Nephrolepidina from the Abuta Limestone Member of the Idozawa Formation and the planktonic Foraminifera from several localities of each formation are treated in detail

Miogypsinid Foraminiferal Biostratigraphy from the Oligocene to Miocene Sedimentary Rocks in the Tethys Region

[出版社版

A new Foraminifera from the upper Middle Eocene of the Ebro Basin, Spain

Volume: 3Start Page: 259End Page: 26

Larger foraminiferal biostratigraphy of the middle Tertiary of Bey Daglari Autochton, Menderes-Taurus Platform, Turkey

Larger foraminifera are recognized from the middle Tertiary (Oligocene-Miocene) carbonate sediments, Bey Daglari Autochton, which is a segment of a Tethyan Platform. Eight diagnostic species and their local ranges are documented. These 8 species establish three biostratigraphically useful faunal assemblages which are assigned to Tertiary e4 (Chattian), Tertiary e5 lower (Aquitanian) and Tertiary e5 upper (Burdigalian) of the Far Eastern Letter Stages. Diagnostic miogypsinid foraminifera and one new genus. Spinosemiogypsina antalyaensis, n. gen., n. sp. are described

Late Oligocene larger foraminifera from the Komahashi-Daini Seamount, Kyushu-Palau Ridge and their tectonic significance

Volume: 4Start Page: 191End Page: 20