Fairly well-preserved external molds of articulated starfish and brittle stars from the upper Albian (mid-Cretaceous) Hokahira Member of the Enokuchi Formation (Goshoura Group) in Goshoura Island (Kumamoto, southern Japan), are described as new species; Coulonia hokahira sp. nov. and Ophiozonella tumidasquama sp. nov., respectively. Of Coulonia, three Early to mid-Cretaceous species are known to date from Texas (USA), Europe and North Africa. The new Japanese species differs from two of these (C. reidi and C. platyspina) in having a proportionally narrower marginal border, and from the third (C. neocomiensis) in having a broader disk. With regard to the brittle stars, it can be stated that the three extinct species previously assigned to Ophiozonella (O. stoehrae, O. eloy and O. thomasi), from Barremian and Aptian (Lower Cretaceous) strata in Europe and the USA, differ from O. tumidasquama sp. nov. in having four spine articulations on lateral arm plates.

This study reports the preliminary results of the first analysis of benthic foraminifera of seafloor surface sediments from the Nishinoshima volcanic area. The samples were collected in 2015 during several DEEP TOW (deep ocean floor towed survey system) dredges on the summit and flank of Nishinoshima-Minami Knoll, a knoll ∼8 km southeast of Nishinoshima Island that forms part of the same submarine volcanic edifice. The two stations DT-1170 (N9) and DT-1173 (N12) were sampled from water depths of 1062–1015 m and 516–203 m, respectively, and were located at distances of 10 and 8 km from the main Nishinoshima edifice, respectively. The two stations displayed a typical faunal structure for deep-sea environments, with low foraminiferal densities but highly diversified assemblages. A total of 131 species, excluding undetermined porcelaneous and hyaline species groups, were found, and are recent deep-sea benthic foraminifera previously identified in the bathyal depths around Izu-Bonin volcanic arc, or species found in the Neogene land-based strata in the western Pacific region. We conclude that the bathyal benthic foraminiferal assemblages in the studied area are likely to be free from recent volcanic activity. We provide detailed taxonomic descriptions of the 21 commonly occurring species. This exploratory study therefore provides crucial basic information about benthic foraminiferal faunas in the Nishinoshima area, which could be used in future environmental analysis of this highly dynamic region.

The Upper Pliocene Motojuku Group (ca. 3.5 Ma) is a well-known Japanese insect fossil locality distributed in the border area between Gunma and Nagano prefectures. Here, we report Tetrapentatoma nishizawai gen. et sp. nov., a new fossil genus and species of the true bug or heteropteran family Pentatomidae from the “Kabutoiwa Formation” of the Motojuku Group. The specimen exhibits morphological characteristics typical of the subfamily Pentatominae of the family except for its distinct four-segmented antennae. The new genus is asserted to be a member of the Pentatoma-complex (included in the tribe Pentatomini of Pentatominae) and is distinguished from the other pentatomid genera by the following characteristics: body approximately 25 mm, broadly ovate; head tongue-shaped; mandibular plates reaching a level of apex of clypeus; antenna four-segmented; antennal segment II longest among segments, 1.4 times as long as segment III; scutellum subtriangular, reaching posterior margin of abdominal tergite VI; hemelytral vein inconspicuous; and connexivum with dark spots. This discovery is the oldest fossil record of the Pentatoma-complex.

We studied fossil benthic foraminifera in three and seven sediment cores from the Nakdong River delta and of off Fukuoka, respectively, to assess sedimentation along the coasts of the strait between Korea and Japan during the early Holocene. Fossil benthic foraminifera in coarse-grained deposits/sandy sediments from ∼9.4–9.3 ka in cores ND-01 and KND-3 of the Nakdong River delta are characterized by a mixture of shallow-water and offshore species. These data suggest the development of transgressive deposits at ∼9.4–9.3 ka, likely associated with sea-level rise driven by the rapid retreat of glaciers at high latitudes (e.g. Laurentide Ice Sheet). Off Fukuoka, two clusters represent high-energy conditions characterized by common occurrences of attached benthic foraminifera; these clusters became dominant in the upper parts of our study intervals. Such attached species occurred commonly earlier, at around 10 ka, at deep offshore sites (> 60 m water depth) relative to shallow sites (< 60 m water depth). These findings are consistent with the development of current-dominated deposits at deep offshore sites at around 10 ka. Transgressive deposits in the Nakdong River delta and abundant attached species off Fukuoka at around 9 ka likely resulted from sea-level rise along the coasts of the strait between Korea and Japan driven by intermittent enhancement of the Tsushima Warm Current.

Two darkling beetles from the subfamily Lagriinae from the late Pliocene of Japan, Kabutoiwa Member (early Piacenzian, ∼3.5 Ma) of the Motojuku Formation are discussed: Lagria koshimizui sp. nov. and Lagria aff. formosensis Borchmann, 1912. These are the first members of the family Tenebrionidae recorded from Pliocene and the first clearly documented fossil species of the genus Lagria. The new species differs from all extant East Asian congeners in the elliptical and short female antennomere 11, which is less than two times as long as previous one. The second species appears very similar to Lagria formosensis Borchmann, 1912, but we cannot assign it to this species with certainty. The absence of Lagria koshimizui sp. nov. and L. aff. formosensis in the contemporary fauna of the main Japanese islands may point on the possible thermophily of both these species and their subsequent extinction.

A new genus Mosirites is herein erected for a Cretaceous heteromorph ammonoid that ranges from the upper Albian to the lower Cenomanian of Hokkaido. The new genus differs from previously described genera of the family Anisoceratidae by its large, loosely coiled, early helical whorls followed by loosely coiled elliptical planispiral whorls. Two new species, M. serpentiformis sp. nov. and M. mirabilis sp. nov., are described from the upper Albian and the upper Albian to lower Cenomanian interval, respectively. Mosirites was probably derived from Anisoceras during late Albian time and flourished during late Albian to early Cenomanian time in the North Pacific region.