Foraminiferal assemblage distribution was used to reconstruct the palaeoenvironmental conditions that prevailed during the deposition of the core MD179-3312 in the eastern margin of the Japan Sea. One hundred six benthic foraminifera species belonging to 50 genera and seven planktonic foraminifera species belonging to three genera were identified in this core. Cluster analyses of both benthic and planktonic foraminifera data led to the identification of seven biofacies which demonstrate the palaeoceanographic history of the Japan Sea since 130 cal kyr BP. Species diversity, evenness and dominance were measured to understand effects of environmental changes on benthic foraminifera distribution. The results indicate that changes in organic matter and oxygen content throughout the core clearly influence community structure of benthic foraminiferal assemblages and species diversity. The light colored non-laminated layers found in particular at the lowermost and uppermost core areas indicate both high diversity and equitability, corresponding to high vertical mixing and good ventilation of subsurface water which would produce suitable living environments for most species; conversely, the dark colored thinly laminated layers (TL layers), in particular TL-1 and TL-2, indicate both low diversity and equitability, corresponding to dysoxic conditions caused by a severe decrease in bottom water oxygenation which would produce unsuitable living environments for most species, with only a few species adapted to this depleted oxygen condition able to survive.

Nine ammonoid species are reported from the Maastrichtian Senpohshi Formation exposed along the western coast of Akkeshi Bay, eastern Hokkaido, and their respective chronologic assignments are discussed on the basis of a previous magnetostratigraphic study. Pachydiscus flexuosus occurs in the lower and middle parts of the formation (= polarity chron C31n, i.e., middle to upper middle Maastrichtian). Gaudryceras makarovense, Anagaudryceras matsumotoi and Diplomoceras cf. notabile and P. flexuosus as well occur in the lower part (middle middle Maastrichtian). The uppermost part of the formation (= probably the lower part of polarity chron C30n, i.e., lower upper Maastrichtian) is fossiliferous and yields a diverse ammonoid assemblage including Neophylloceras sp., Pseudophyllites sp., Zelandites varuna, A. matsumotoi, Gaudryceras cf. seymouriense, Gaudryceras sp., and D. cf. notabile. Integration of bio- and magnetostratigraphy in the Senpohshi Formation makes it possible to determine precise and detailed chronologic assignment of strata containing similar faunas in the Northwest Pacific realm.

We describe a new deep-sea arcid species, Bentharca steffeni sp. nov., from the Paleocene Katsuhira Formation in Urahoro Town, eastern Hokkaido. This is the oldest certain record of this genus. Shell microstructure of this new species is similar to the Recent species, B. asperula (Dall, 1891) in having an outer layer composed of thin simple lamellar fibrous prismatic and crossed lamellar structures and an inner layer composed of irregular complex crossed lamellar and irregular prismatic structures. Of these, the simple lamellar fibrous prismatic and the irregular prismatic structures have never previously been recognized even in B. asperula. From the occurrence of the new species, it has been elucidated that the genus Bentharca adapted to the deep sea as a refuge at least in the Paleocene.

A fossil rhinocerotid tooth from the Yage Formation (Middle to Late Pleistocene), Yage in Shizuoka Prefecture, is described. The present specimen shows the following characteristics of the second lower incisor: tusk-like shape, enamel on the labial side, a teardrop-shaped cross section of the tooth crown, and an oval cross section of the root. The specimen is similar to the genus Rhinoceros in having a large and robust shape. However, owing to a lack of other elements, generic and specific identification are not possible. Previously, several large mammal fossils had been reported from the Yage area, but there were no rhinocerotids among them. Thus, this report is the first record of a rhinocerotid from the area. The Yage specimen suggests rhinocerotids were widely distributed during the Pleistocene of Far East Asia.

In this paper, we describe newly discovered and previously collected fossil moschid specimens from the middle Miocene of China. Besides the previously reported Hispanomeryx andrewsi, we recognize four additional fossil species in two genera of Moschidae in the middle Miocene of China based on dental morphology: Micromeryx cf. flourensianus, Micromeryx sp., Hispanomeryx sp. 1, and Hispanomeryx sp. 2. The specimens are of Tunggurian age (Neogene Chinese Land Mammal Age), corresponding to European MN6-MN7/8. The records show a diversity of fossil moschids in the middle Miocene of China comparable with the contemporaneous diversity in western European faunas.

An early Permian (Kungurian) brachiopod fauna, consisting of 15 species in 15 genera, is described from the lower part of the Hosoo Formation of the Nakadaira area, South Kitakami Belt, northeastern Japan. The new species is Thamnosia nakadairensis. The Nakadaira fauna is a mixed Boreal—Tethyan fauna, with a close affinity to the early Permian brachiopod faunas of northwestern China (Xinjiang) and northern China (Inner Mongolia and Shanxi). The South Kitakami Belt was probably located in a transitional zone between the Boreal and Tethyan realms, developed along the eastern margin of North China (Sino—Korea) in the early Permian (Kungurian).