ZooBank registration: urn:lsid:zoobank.org:pub:F8EDB286-64B8-4125-907E-4863368BF2DA

Relative sea level (RSL) changes in tectonically active areas might differ significantly from the global signal. Regional proxy data of tectonically active areas such as Taiwan are indispensable for constraining models on global sea-level change. Ostracod assemblages were examined in here to clarify paleoenvironmental and RSL changes in Dapeng Bay, Southern Taiwan. Overall, 13 genera and 16 species of ostracods were identified from two cores taken in the northern parts of the bay. Based on ostracod assemblage changes, RSL in Dapeng Bay suggested a gradual increase from about 10 to 2 m below the present sea level over the past 2000 years, although two century-scale relative highs in RSL were identified. The general trend of the increasing RSL over the past 2000 years corresponds to the subsidence rate around the study area. Two coeval RSL highs were recognized on the coasts of China and Taiwan between 500–700 CE and 1200–1400 CE, suggesting that a common factor affected the century-scale sea-level changes around Taiwan and China. Salinity in Dapeng Bay is controlled by precipitation influenced by regional and global climatic factors, including the East Asian summer monsoon (EASM) and El Niño–Southern Oscillation (ENSO).

A total of 52 ostracod species were found in 24 samples collected from four sites of the Yoshino Formation of the Katsuta Group, which were deposited in the Setouchi Geologic Province of southwestern Japan during the mid-Miocene Climatic Optimum (16.9–14.7 Ma). Q-mode cluster analysis revealed five sample clusters (ostracod biofacies), suggesting that the paleoenvironments included enclosed bay, middle to lower sublittoral bay, and upper bathyal sea, in ascending order, during the transgression. R-mode cluster analysis revealed seven species clusters (ostracod bioassociations) that reflect the paleoecology of ostracod species. Fossil ostracod assemblages are paleobiogeographically characterized by a mixture of tropical taxa (e.g. Cibotoleberis, Pacambocythere, and Paijenborchella), cosmopolitan taxa (e.g. Cytherella, Neonesidea, and Xestoleberis), and the taxa that survived or evolved around the Japanese islands since the Paleogene (e.g. Acanthocythereis, Munseyella, Pseudoaurila, and Trachyleberis). All taxa entered the study area after the opening of the Sea of Japan during 18–17 Ma. Cool-temperate species, such as Elofsonella, Hemicythere, and Laperousecythere, which have been reported from the Lower Miocene deposits in Japan, were not detected in the study area. Three new trachyleberidid species, Acanthocythereis kunihiroi sp. nov., Cibotoleberis tsuyamensis sp. nov., and Pacambocythere ishizakii sp. nov., are described.

The discovery of excellently preserved articulated plant fossils from the Oxfordian (Upper Jurassic) Tochikubo Formation of Shidazawa, Minamisoma, Fukushima, northeast Japan, allows for the description and reconstruction of the new fossil whole-plant bennettitalean Ohaniella ptilofolia gen. et sp. nov., based on preserved axes with attached foliage of the Ptilophyllum jurassicum-type and attached ovuliferous reproductive structures (flowers/seed cones). Recent excavations unveiled plant fossils with axes carrying a whorl of apically arranged leaves, in the centre of which remnants of ovuliferous reproductive structures in the form of possible seed cones are preserved. The findings of Weltrichia-like microsporangiate flowers in the same bedding planes on slabs exclusively yielding foliage of the Ptilophyllum jurassicum-type suggest that (a) these might have been produced by the plants carrying Ptilophyllum jurassicum-type foliage and just have been shed as was the case in the closely related Kimuriella densifolia, and (b) Ohaniella ptilofolia gen. et sp. nov. plants might have formed more or less monotypic stands of shrub thickets referring to special environmental conditions and requirements.

Two specimens of fossil lipotid have been recovered from the Upper Miocene of Gunma and Tochigi prefectures, Japan. The specimens consist of crania including periotic and tympanic bullae. We describe and diagnose the specimens as a new genus and species of the family Lipotidae, Eolipotes japonicus, gen. et sp. nov. The paratype of E. japonicus, GMNH-PV-1011, was found stratigraphically between two tuff layers and a well constrained age interval (11.29–11.25 Ma) can be proposed, indicating that E. japonicus is the oldest precisely dated lipotid species yet described. Phylogenetic analysis revealed that E. japonicus is more closely related to Parapontoporia spp. than to the recently extinct Yangtze river dolphin, Lipotes vexillifer. Given the phylogenetic relationships and parsimonious distribution of the event to fluvial invasion in Lipotidae, it is suggested that at least two independent invasions to the freshwater habitat occurred in Lipotidae.

A new fossil species of the genus Archaeromma Yoshimoto, 1975 was discovered in Iwaki amber from the Tamayama Formation (Late Cretaceous Coniacian) in Iwaki City, Fukushima Prefecture, Japan. The genus Archaeromma belongs to the family Mymarommatidae, and the members are called false fairy wasps because of their small bodies; only 10 species have been described from Cretaceous amber (Albian to Campanian). In this paper, we have described the new fossil species as Archaeromma chisatoi sp. nov. To the best of our knowledge, this is the second report of a fossil of the genus Archaeromma from Japan; the first one was found in Kuji amber, Iwate Prefecture. However, this is the first report of a fossil species from the Coniacian age and the first paleontological description from Iwaki amber.

Two new diatom species, Praestephanos tokaiensis sp. nov. and P. miensis sp. nov. are described from lacustrine deposits in the Pliocene Ueno Formation of the Kobiwako Group in Iga City, Mie Prefecture, Japan. The stratigraphic ranges of P. tokaiensis and P. miensis are approximately 3.9–3.8 Ma and 3.8–3.7 Ma, respectively. The morphology of these species is mainly characterized by a slightly doubly undulating central area; this feature is not found in previously described Praestephanos species or similar Stephanodiscus species. The stratigraphic distribution and morphology of the two new species suggest that P. tokaiensis and P. miensis have an ancestor–descendant relationship.

A bedded chert succession, intercalated with layers of coarse-grained sandstone and chert conglomerate, and a limestone block with a long axis of about 10 m are distributed in the Ban Rai area, southwestern Uthai Thani, central Thailand. The chert yielded early Carboniferous (Tournaisian to Visean) radiolarians composed of 10 species of five genera; the limestone yielded Middle Triassic (early Anisian) conodonts comprising five species (P1 element). The lower Carboniferous chert was presumably deposited on the upper continental rise of the Sibumasu Terrane in the Paleotethys Ocean, based on radiolarian faunal characteristics. The Middle Triassic limestone was probably deposited on the continental shelf of the eastern margin of the Sibumasu Terrane, judging from the inclusion of silt-sized quartz grains. Because the blocks of the lower Carboniferous chert and Middle Triassic limestone are currently located in a narrow area, these blocks are inferred to have been mixed with each other by submarine sliding after at least the Middle Triassic at the eastern margin of the Sibumasu Terrane.

The Triglypta–Qaidamestheria clam shrimp assemblage, widely known from the non-marine Jurassic deposits in northern China, is important for biostratigraphic correlation of the fossil bearing strata. QaidamestheriaWang, 1983, an essential component of the assemblage, was originally described from the upmost oil shale member of the Dameigou Formation at the northern margin of the Qaidam Basin, northwest China. Though the original description of the genus Qaidamestheria was based on SEM microscopy, the published pictures of the type specimens are unclear, and the type specimens were lost. We collected new specimens of the type species Qaidamestheria dameigouensisWang, 1983 from the 7th unit of the Dameigou Formation in the Dameigou section, where the holotype of the species was originally collected. The examination of the specimens under SEM has revealed three critical taxonomic features for the genus: the fine reticulation (mesh diameter 7–18 µm) on the larval valve and several adjacent growth bands; the transitional (reticulated-punctate) ornamentation on the middle–ventral part of the carapace; and linearly arranged puncta appearing only on growth bands near the antero-ventral margin of the carapace, puncta never clustered.