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Volume 1989 (1989)
- Issue 156 Pages 255-
- Issue 155 Pages 141-
- Issue 154 Pages 59-
- Issue 153 Pages 1-
Volume 1989, Issue 153
Displaying 1-5 of 5 articles from this issue
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HIROSHI NISHI, SATOSHI YOKOTA, TSUNEMASA SAITO1989 Volume 1989 Issue 153 Pages 1-11
Published: April 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSA fairly well-preserved planktonic foraminiferal assemblage was recovered from the Hinagu Formation when recovery of radiolarian was attempted from a siliceous mudstone by applying the hydrofluoric acid extracting method. The assemblage comprises Globigerinelloides barri (Bolli, Loeblich and Tappan), Hedbergella delrioensis (Carsey), H. planispira (Tappan), H. trocoidea (Gandolfi), and Ticinella primula Luterbacher. The joint occurrence of the Albian species of T. primula and G. barri which had been known only from the late Aptian is used to establish an early middle Albian age of the fauna. An ammonite assemblage consisting of two species had previously been used to assign an early Aptian age to the lower half of the Hinagu Formation. This ammonite age contradicts ages indicated by both planktonic foraminifera and radiolarians. The Yatsushiro Formation which is considered to unconformably overlie the Hinagu Formation also had been dated by ammonites as late early Albian. Microfossil ages are not yet available for this formation. If the ammonite age is unequivocal for this formation, those ammonite-bearing lithofacies labeled as the Yatsushiro Formation are likely to be a coeval but shallower water facies of the Hinagu Formation.View full abstractDownload PDF (1527K) -
TATSURO MATSUMOTO1989 Volume 1989 Issue 153 Pages 12-24
Published: April 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSInoceramus pictus Sowerby is well known for its world-wide distribution in the upper part of the Cenomanian. For some reasons, however, no example of this species has been described from Japan. I. pictus is regarded as highly variable and currently divided into more than six subspecies. Some of them are reviewed in this paper for careful comparison with our forms. I have realized that some specimens of rather old collections from several localities in Hokkaido are referable to this species, although they are atypical. They are described in this paper under a new subspecies, which is distinguished from I. pictus pictus by its less distinctly marked growth striae, finer rings and weaker concentric subcostae and/or undulations, instead of pronounced major ribs or folds. The form from Kamchatka called "I. pictus neocaledonicus" by Pergament may be preferably transferred to this new subspecies.View full abstractDownload PDF (2747K) -
SABURO KANNO, KAZUTAKA AMANO, HIROMITSU BAN1989 Volume 1989 Issue 153 Pages 25-35
Published: April 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSCalyptogena (s.s.) pacifica was discovered from the Neogene System in the western part of Joetsu City. This species occurs from four localities in the turbiditic strata, and its occurrences show the autochthonous in three localities whereas allochthonous in the rest. This species was associated with deep-sea bottom dwellers in all localities. At the present, this species seems to be restricted in the Neogene System of western Hokkaido to Niigata Prefecture along the Japan Sea. The ratios of shell height to length become small as to shell growth, and the beaks situate more anteriorly in adult age than the younger one. The teeth fairly vary in their growth stages, and become more simple in adult than that of younger one. There are some relationship between the growth of individuals of C. (s.s.) pacifica and the size of their shell colonies. The shell colonies of fossil Calyptogena seem to suggest an indicator of the extinct venting area in the geologic time. The writers pointed out the confusion among the previous workers on the type locality of C. (s.s.) pacifica.View full abstractDownload PDF (1577K) -
TAKESHI KOZAI1989 Volume 1989 Issue 153 Pages 36-47
Published: April 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSThis paper contains the revised descriptions of five species from Japan, which were referred to Nipponicorbula, Corbula and Eoursivivas. The genus Eoursivivas is ranked down to the subgenus of Corbula, and Corbula (Varicorbula) ushibukensis Tashiro et Otsuka is transferred to Corbula (Bicorbula). In addition, a new species of Corbula (Bicorbula) is established on the material from the Maastrichtian Upper Himenoura Subgroup of Kumamoto Prefecture. The environments inhabited by Nipponicorbula mifunensis Ota and Nipponicorbula mashikensis Tamura are discussed.View full abstractDownload PDF (1794K) -
TSUGIO SHUTO1989 Volume 1989 Issue 153 Pages 48-54
Published: April 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSGemmuloborsonia, a new genus of the Borsoniinae, Turridae, Neogastropoda is proposed here on the type-species, G. fierstinei, sp. nov. from the Plio-Pleistocene Cabatuan Formation on Tambac and other islands in Tambac Bay, the Bolinao district, Northwest Luzon. Gemmuloborsonia shows superficial similarity to Kuroshioturris Shuto, 1961, of the Turrinae in the shell-profile, protoconch, sculpture and anal sinus, but is readily distinguished from the latter in being provided with a distinct columellar plait. The genus includes four species from the Upper Miocene and Plio-Pleistocene of the Mediterranean and Malayan regions.View full abstractDownload PDF (1017K)
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