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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 155
Displaying 1-7 of 7 articles from this issue
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TATSUAKI KIMURA, BONG KYUN KIM1989 Volume 1989 Issue 155 Pages 141-158
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSContinued from our previous issue (Part 1), this paper deals with the description of the following newly recognized taxa in the Daedong Flora : Pterophyllum cheondaeriense, sp. nov., Anthrophyopsis decurrens, sp. nov., Drepanozamites sp. A, Podozamites ex gr. schenki Heer, P. sp. A, Cycadocarpidium sp. cf. C. asaense Kon'no, C. sp. cf. C. nagatoense Kon'no, C. sp. A, Taeniopteris cheondaeriensis, sp. nov. and T. mungyeongensis, sp. nov.View full abstractDownload PDF (2590K) -
YOSHINARI KAWAMURA, KAZUAKI IIDA1989 Volume 1989 Issue 155 Pages 159-168
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSA murid M1 obtained from the Hiraen Clay Member of the Kobiwako Group is the oldest record of the family in the Japanese Islands. The molar is assigned to the small Japanese field mouse, Apodemus argenteus, an endemic species living in the islands today. It indicates that this species originated by the early Middle Pleistocene (0.65-0.7 Ma). Moreover, the molar contributes to reconstructing the Quaternary mammalian faunal succession in Japan, because the faunal content of mammalian biozone QM3 (0.5 to 0.73 Ma) is poorly known.View full abstractDownload PDF (1057K) -
YOSHIHIRO TANIMURA1989 Volume 1989 Issue 155 Pages 169-177
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSA new pennate diatom, Denticulopsis praehyalina, from the early Middle Miocene diatomite of the Oki Islands is described. This species has many affinities to Denticulopsis hyalina but differs from it by having areolation on valve face. The new species combines morphological features of two Denticulopsis species, D. hyalina and D. lauta. A predominance or acme of D. praehyalina is restricted to the uppermost part of Middle Miocene D. hyalina Zone in the Northwest Pacific, and it is a good maker for the horizon.View full abstractDownload PDF (2194K) -
TATSURO MATSUMOTO, AKITO ASAI1989 Volume 1989 Issue 155 Pages 178-196
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSIn this paper Birostrina nipponica (Nagao et Matsumoto, 1939) is redefined and fully described. It is markedly inequivalve, with very small or scarcely discernible posterior wing ; left valve is very convex, with much incurved umbo ; ornament is fine and weak. This species is very variable and includes at least three forms, viz. (α) slender form with a strongly projected left umbo, (β) form with subrounded main part of valve which shows a uniform convexity and (γ) narrowly convex form with a summit along the growthaxis. The three forms seem to intergrade. None of them is identical to any of the variable forms of Albian B. concentrica (Parkinson) nor to Middle Cenomanian B. tamurai which has a posterior radial groove and develops irregular ribs in late growth-stage. Some of the specimens hitherto called Inoceramus concentricus var. nipponicus are transferred to certain other species. For instance, those from the Zone of Mantelliceras japonicum (Lower Cenomanian) should be mostly referred to I. tenuis Mantell ; a few are to be referred to a Turonian species allied to I. inaequivalvis Schluter. B. nipponica in a revised sense occurs so far from the high Middle to low Upper Cenomanian of Hokkaido and Sakhalin. A form represented by several specimens is allied to but different from this species and described tentatively under B. aff. nipponica.View full abstractDownload PDF (5702K) -
NATSUHIKO KOJIMA1989 Volume 1989 Issue 155 Pages 197-211
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSDinoflagellate cysts occur in the Holocene sediments of Lake Hamana, Central Japan. The cyst assemblages are dominated by Brigantedinium spp., Selenopemphix quanta and Seleno. hamanaensis of the Peridinioid Lineage, and Polykrikos schwartzii, Poly. kofoidii and Pheopolykrikos hartmannii of the Gymnodinioid Lineage. A few cysts of the Gonyaulacoid and Tuberculodinioid Lineages are also present in the samples. Six dinoflagellate cyst assemblage zones are established based on differences of species composition. From the cores of central Lake Hamana, environmental changes from stable inner bay to brackish-water lake and then to freshwater lake and finally to brackish-water lake were recorded in the cyst composition. One new species, Selenopemphix hamanaensis, and four cysts are described.View full abstractDownload PDF (3106K) -
MASAYUKI EHIRO, FUMINORI TAKIZAWA1989 Volume 1989 Issue 155 Pages 212-217
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSTwo specimens of nautiloids, identified as Foordiceras cf. F. wynnei and Domatoceras ogatsuense, n. sp., are described from the Lower Toyoman Series (Upper Permian, Dzhulfian) in the Southern Kitakami Massif. The genus Foordiceras is first described from the Dzhulfian in Japan, and the genus Domatoceras is also first recorded from Japan in this paper. These nautiloids are closely related to those from the Dzhulfian beds of the Central Tethys.View full abstractDownload PDF (1185K) -
SATOSHI CHIBA1989 Volume 1989 Issue 155 Pages 218-251
Published: September 30, 1989
Released on J-STAGE: May 25, 2010
JOURNAL FREE ACCESSFifteen fossil and extant species including seven new species of the Pleistocene. Recent land snail genus Mandarina (Pulmonata ; Camaenidae) of the Bonin Islands are described, and their morphologic and possible interspecific relationships are considered. Mandarina has undergone remarkable adaptive radiation in this small, isolated archiperago. The diversified shell morphology of these snails is characterized by complex allometric trends generated by the interplay of juvenile shell form and later shell growth patterns. Morphologic features in the juvenile stage are little influenced by habitat conditions, and the classification of species based on juvenile shells matches well with that based on genitalia. In contrast, adult shell characters are strongly influenced by environmental conditions, suggesting that they are useful to consider habitats of fossil species. Phylogenetic relationships of these species were preliminarily reconstructed from quantitative analysis of juvenile shell and penial morphology. It is assumed that not only distinct diversification of shell morphology in the same stock but also convergence of adult shell features between the two species of different stocks has been occurred.View full abstractDownload PDF (3940K)
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