We document the occurrence of Early Triassic (Olenekian) crinoid ossicles in exotic blocks contained within the black limestone unit of the Thaynes Formation, which overlies the Dinwoody Formation at the classic Crittenden Springs Smithian ammonoid locality. Crinoid ossicles include two species, i.e., Holocrinus sp. and Articulata ord., fam., gen. et sp. indet. Furthermore, two co-occurring, age diagnostic conodonts, i.e., Neospathodus pakistanensis and Ns. posterolongatus, constrain the age of the crinoids from the early Smithian to the earliest middle Smithian. This discovery represents the third report of Smithian Holocrinidae in the Panthalassan area and it provides important data for the study of crinoid recovery during the Early Triassic.

Ontogeny and variation of the three barroisiceratine ammonoids Yabeiceras orientale Tokunaga and Shimizu, Yabeiceras cf. manasoaense Collignon, and Forresteria (F.) yezoensis Matsumoto were studied by means of X-ray micro-computer tomography based on the well-preserved material from the probable upper Turonian Obisagawa Member of the Ashizawa Formation, Futaba Group in Fukushima Prefecture, northeast Japan. Specimens of Y. orientale, F. (F.) yezoensis, and F. (F.) muramotoi from the Coniacian of the Yezo Group in Mikasa City, central Hokkaido, northern Japan were also examined for comparison. As the shell of Y. orientale grows, the relative umbilical size (U/D) becomes rapidly larger at shell diameter (D) of 30–50 mm, and the relative whorl thickness (W/H) first increases to the stage of 30–50 mm in D and then decreases gradually. The growth rate of whorl width in costal section (W) is relatively constant up to a diameter of 30–50 mm and then decreases gradually, whereas that of whorl height (H) is relatively constant throughout ontogeny. The intraspecific variations in U/D and W/H in middle whorls are wider than those in early and late whorls, as evidenced by the data from the present and previous studies. As the shell of F. (F.) yezoensis grows, U/D is almost constant, and W/H decreases gradually after D exceeds 30–50 mm. Forresteria (F.) yezoensis shows relatively narrow intraspecific variations in relative umbilical size and whorl thickness, as evidenced by the measurement data from the present and previous studies.

The Iwaki insect-bearing amber from Fukushima Prefecture, northeastern Honshu, Japan, is considered from the Late Cretaceous Coniacian age. The insect-bearing amber localities from that period are few worldwide. Here, we report Iwakia longilabiata gen. et sp. nov., a new fossil genus and species of the infraorder Cimicomorpha Leston, Pendergrast and Southwood, 1954 (Hemiptera: Heteroptera) from the Futaba Group of Iwaki City. Although the preservation is incomplete, this fossil is provisionally placed in the family Microphysidae Dohrn, 1859 based on the general consistency of the diagnostic characters of the family. The fossil is distinguishable from any genus of Cimicomorpha including Microphysidae because of its long labium and brachypterous female. Additionally, the fossil shares the female diagnostic characteristics of the Palaearctic and Nearctic taxa, suggesting that it is an early stage in the evolution of sexual dimorphism of the family Microphysidae. The evolution of sexual dimorphism in Microphysidae may have already occurred in East Asia during the Late Cretaceous Coniacian age. This fossil may be the first discovery from Asia and the oldest record of the family Microphysidae.

ZooBank registration: urn:lsid:zoobank.org:pub:CC4DAF02-7182-4D9E-871F-A3B81BFFBDFD

Herein, we describe Callorhinchus orientalis sp. nov., an extinct callorhinchid chondrichthyan species found in the lower Maastrichtian deposits of the Hakobuchi Formation in Hobetsu, Hokkaido, northern Japan. This species is the first record of the genus Callorhinchus from the northern Pacific region, filling the biogeographical gap and implying survival beyond the Cretaceous/Paleogene extinction event because of the broad distribution of the genus. A comparison of Maastrichtian Callorhinchus species, including C. orientalis sp. nov., and Danian species indicates a potential period of temporal dwarfing within the genus across this extinction event.

ZooBank registration: urn:lsid:zoobank.org:pub:7ED050DB-7A04-4999-9CA9-8E04E0B5AA56

Five species of Late Cretaceous ammonoids, Yezoceras miotuberculatum, Yezoceras elegans, Eubostrychoceras indopacificum, Pseudoxybeloceras sp., and Yabeiceras orientale, have been identified from the Obisagawa Member of the Ashizawa Formation, Futaba Group, Fukushima Prefecture, northeastern Japan. Notably, Yezoc.miotuberculatum, Yezoc. elegans, and the genus Pseudoxybeloceras, previously known from the Yezo Group in Hokkaido, northern Japan, were identified for the first time from the Futaba Group. The presence of Yezoc.miotuberculatum and Yezoc. elegans indicates faunal similarities between the Ashizawa Formation and the Yezo Group in Hokkaido. Co-occurrence of age-diagnostic inoceramids suggesting latest Turonian to earliest Coniacian age allows us to provide a detailed biostratigraphic correlation between the Futaba and Yezo groups.

This study describes a new fossil butterfly species, Tacola kamitanii sp. nov., from the Upper Pliocene to the Lower Pleistocene Teragi Group in Hyogo Prefecture, Japan. The new fossil is characterized by remarkably large wings, with an estimated forewing length of 48 mm and a wingspan of 84 mm. This new fossil species belongs to the genus Tacola based on the following characteristics: both discal cells open, smoothly curved humeral veins, and a thick thorax and abdomen. However, it does not identify with any modern relatives of Tacola with a small discal cell, straight 1A+2A anal vein of the forewing, or long hindwing median vein. Therefore, the fossil was identified as a new species of the genus Tacola and one of the largest species in the subfamily Limenitidinae. The modern relatives of Tacola are distributed in the subtropics and tropics, while this fossil species may have survived in the temperate zone. This is the first named Limenitidini fossil and the youngest example of an extinct butterfly.

ZooBank registration: urn:lsid:zoobank.org:pub:FCF699C6-B28F-4916-91BE-B9C93A0BB0DC

We review the Anthracotheriidae (Mammalia, Artiodactyla) from the lower part (ca. 15.0–14.4 Ma) of the middle Miocene Aka Aiteputh Formation in Nachola (northern Kenya), with a description of the specimens. The anthracotheriids of the Aka Aiteputh Formation in Nachola consist of two bothriodontine species, Brachyodus aequatorialis nacholaensis subsp. nov. and Nacholameryx baragoiensis gen. et sp. nov. The materials of B. aequatorialis nacholaensis consist of gnatho-dental, phalanx, metapodial, and scaphoid specimens that likely comprise a single individual. B. aequatorialis nacholaensis is distinguished from Brachyodus aequatorialis aequatorialis in having a lingual postprotocrista on P4 and a better developed cuspid on the p4 talonid and in lacking a buccal postprotocristid on p4. The materials of N. baragoiensis consist mainly of isolated teeth. N. baragoiensis is characterized by relatively small body size, tetracuspidate upper molars with a looplike mesostyle and without a lingual postprotocrista, lower molars with a preprotocristid and prehypocristid (cristid obliqua) reaching close to the lingual margin of the crown, a buccally positioned m3 hypoconulid, and a better-developed and isolated paraconid and metaconid (or entostylid) on p4 with an extra cuspid between the protoconid and the paraconid. Our phylogenetic analyses recover Nacholameryx as the sister taxon of the [Merycopotamus + Libycosaurus] clade within the Merycopotamini, raising the possibility that the [Merycopotamus + Libycosaurus] clade originated in Africa during the middle Miocene. This revision of the Nachola anthracotheriids demonstrates that the results of previous faunal analyses of the Nachola mammals should be reappraised.

ZooBank registration: urn:lsid:zoobank.org:pub:46DFEEF0-E0E8-4B80-BD7A-C9BE13B8D70D

Azooxanthellate colonial corals are important habitat-formers in deep-water ecosystems. Here, we provide detailed descriptions of three framework-forming azooxanthellate corals (Petrophyllia niimiensis, Dendrophyllia okamotoi and Dendrophyllia mokiensis sp. nov.) from the Miocene Omori Formation on the Moki coast in Oda, Shimane, Japan using microfocus X-ray computed tomography. With an estimated age of 17.65–13.60 Ma based on nannofossils, Dendrophyllia mokiensis sp. nov. represents the oldest member of Dendrophyllia with a sympodial budding colony. Moreover, this is the first report of the co-occurrence of Petrophyllia and Dendrophyllia in a high density fossil assemblage. Petrophyllia has been reported as a framework builder in cold-water coral reefs or a member of dense accumulations of azooxanthellate corals during the Turonian (Late Cretaceous), thereby raising the possibility that an azooxanthellate coral community dominated by Petrophyllia also existed in the Miocene. This discovery sheds light on changes in azooxanthellate coral communities in deep-water coral habitats during the Cenozoic.

ZooBank registration: urn:lsid:zoobank.org:act:C3FFF753-2212-403F-9743-C84308CC0400

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

The first detailed systematic documentation of Late Ordovician (Katian) ostracods from the Phu Ngu Formation, northern Vietnam, yields nine species, two described in open nomenclature, from seven genera, two identified tentatively, with six new species, including two new palaeocopine species, five binodicopine species (three new species, including one new genus, one species described in open nomenclature, and the previously described Kinnekullea gaia Wong Hearing et al.), one new leiocopine species and a possible metacopine species. The ostracods co-occur with brachiopods, trilobites and graptolites, in lithofacies interpreted as deposited in a deep marine paleoarc setting on the South China paleoplate. Several ostracod genera from the Phu Ngu Formation are known from paleocontinents that were remote from South China during the Ordovician, including Baltica, Laurentia and the Argentine Precordillera. Assessing the taxonomic composition of the Phu Ngu ostracod assemblage, alongside other Ordovician ostracod faunas from the South China paleoplate reveals that there are very few endemic genera and high proportions of cosmopolitan genera, questioning the utility of ostracod genera for paleogeographical determination, and raising the possibility they were able to migrate via deep, cooler ocean waters.

ZooBank registration: urn:lsid:zoobank.org:pub:622C3839-363F-4B01-89C1-B8ACFA077279

Distribution contour maps of aquatic palynomorphs in Osaka Bay were made to determine their horizontal distribution using 21 surface sediment samples. The aquatic palynomorphs consisted of planktonic autotrophic dinoflagellate cysts, raphidophyte cysts, heterotrophic dinoflagellate cysts, heterotrophic ciliate cysts, heterotrophic crustacean resting eggs, benthic foraminiferal linings, turbellarian egg capsules, as well as planktonic chlorophycean resistant cells. Most of these resistant cells are thought to have been transported via the Yodo River (Yodogawa), since most of them originated from freshwater areas, mainly Lake Biwa. Most of these palynomorphs were distributed mainly off the mouth of the Yodo River, while benthic foraminiferal linings were distributed mainly off Kobe Airport. A canonical correspondence analysis between each palynomorph and environmental factors including distance from the mouth of the Yodo River (Distance A), water depth, dissolved oxygen (DO), surface water temperature, salinity, transparency, grain size composition (Mdφ), chemical oxygen demand (COD), nitrogen, phosphorus, and chlorophyll was performed. The results showed that the autotrophic dinoflagellate Spiniferites bulloideus and foraminiferal linings were strongly positively correlated with Distance A and Mdφ but negatively correlated with DO, whereas cysts of Alexandrium catenella/pacificum, which often form red tides with paralytic shellfish poisoning in Osaka Bay, were positively correlated with water depth and negatively correlated with COD. Turbellarian egg capsules, heterotrophic dinoflagellate cysts, Echinidinium spp., and foraminiferal linings were positively correlated with salinity and transparency. However, these results do not logically explain the relationship between the distribution of these palynomorphs and environmental factors, because the distribution of aquatic palynomorphs in a narrow sea area with complex marine environments such as Osaka Bay is caused by a combination of biological factors and physical factors that act after the formation of palynomorphs.

The westerlies, a major atmospheric circulation system, have a crucial role in driving climate and environmental changes in the middle latitudes of the Northern Hemisphere, particularly in arid Central Asia (ACA). However, the influence of variations in the westerlies on biota remains elusive due to less sedimentary archives. Here, we focus on Holocene ostracods from a core in the Bosten Lake in Xinjiang of the ACA area. We conducted a comparative analysis of our ostracod records, including radiocarbon dating results, with ostracod and salinity records from other cores within Bosten Lake, and suggested that alternative ostracod assemblages can serve as indicators of salinity changes in the lake over the past 8,000 years, which corresponded to westerlies dynamics. We propose that over the course of 8,000 years, precipitation patterns in the Bosten Lake region were influenced by intensified westerlies, which were associated with high sea surface temperatures (SSTs) in the North Atlantic. This climatic shift, in turn, led to changes in the local ostracod communities.

A new species of nostoceratid ammonoid, Eubostrychoceras perplexum sp. nov., is described from the Santonian (Upper Cretaceous) in the Tappu, Kotanbetsu, and Haboro areas of Hokkaido, northern Japan. The diagnostic features of E. perplexum sp. nov. are tightly coiled, slowly enlarging whorls with a small apical angle, a small umbilicus, and a rounded rectangular whorl section. In addition to Hokkaido, the new species is also recorded from Wakayama, southwestern Japan. Given that the occurrence of this new species might be limited to the uppermost Santonian, it may thus serve as a useful indicator of stratigraphic correlation in the northwestern Pacific region. Although the new species cannot be assumed to have a direct phylogenetic relationship with any of the described Eubostrychoceras species, Hyphantoceras orientale (Yabe) is established to have multiple characters in common with E. perplexum sp. nov., and both species occur sympatrically in the upper Santonian. However, as E. perplexum sp. nov. lacks rows of tubercles, it does not satisfy the definition of the genus Hyphantoceras and accordingly cannot be placed within this genus. Nonetheless, the plausibility of a phylogenetic relationship between the two species cannot be ruled out. This contradiction between taxonomic evaluation and phylogenetic estimation raises questions regarding the current taxonomic criteria used to classify genera within the family Nostoceratidae.

ZooBank registration: urn:lsid:zoobank.org:pub:A4DCCCF7-3AD9-4B8F-800D-9BCB95F48788

Here, we report the first discovery of Mesozoic insect fossils from the Late Cretaceous of Kyushu Island, Japan. The specimens include an isolated abdomen (Insecta, fam., gen. et sp. indet.) from the Santonian Hinoshima Formation in Kumamoto, and an isolated elytron (Coleoptera, fam., gen. et sp. indet.) from the Campanian Mitsuse Formation in Nagasaki. Although the preservation of fossils does not allow for species-level identification, these finds represent a crucial initial step toward understanding insect diversity and the composition of terrestrial ecosystems in the eastern margin of East Asia during the Late Cretaceous.

Unio ogamigoensis, the first unionid bivalve reported from the Tetori Group, is redescribed as Margaritifera ogamigoensis on the basis of the hinge teeth and muscle attachment scars of the holotype and newly added specimens from the Kuwajima Formation of the Tetori Group, central Japan. This species occurs within crevasse splay sandstones that are intercalated with the fluvial floodplain deposits of the meandering river system. Nakamuranaia kagaensis, which is commonly found in muddy fine-grained sandstone and mudstone in the overbank deposits, is also redescribed from Archaeounio kagaensis, i.e., Archaeounio becomes a synonym of Nakamuranaia. The mode of occurrence of the two species indicates that M. ogamigoensis was a rapidly flowing stream dweller, whereas N. kagaensis inhabited stagnant shallow oxbow lakes.

Fourteen species of late Albian ammonoids, including a newly described species [Desmoceras (Pseudouhligella) trigonum sp. nov.], are reported from the Hokahira Member of the Enokuchi Formation, Goshoura Group in the Tateishibana area of Shishijima in Kagoshima, Kyushu, Japan. This ammonoid fauna resembles the late Albian ammonoid fauna of the Tethyan biotic realm as it includes genera such as Desmoceras (Desmoceras), Cantabrigites, Mortoniceras, Anisoceras, Hamites, Hemiptychoceras, Pseudhelicoceras, Lechites, Scaphites and Worthoceras, while it also includes species endemic to the Northwest Pacific region, such as D. (Pseudouhligella) shikokuense and D. (P.) trigonum sp. nov. The post-Albian early Cenomanian ammonoid fauna of the Northwest Pacific region is distinct from that of the Tethyan biotic realm and is characterized by many endemic species and remnants of the late Albian and their descendants. A cooling event may have occurred near the Albian–Cenomanian boundary that separated the faunas of the Tethys and North Pacific regions, and the late Albian ammonoids reported herein probably represent a fauna from just before that event occurred.

ZooBank registration: urn:lsid:zoobank.org:pub:7A331E27-05A3-4308-8F51-7AB704DDB6DA

Fossils of bumblebees and their kin (Bombini) are extremely rare, with only 15 occurrences from the Upper Eocene to Upper Miocene representing 14 species reported to date, all of which are extinct. Here, we report a new bumblebee (Bombus) fossil, a queen bee from the Middle Pleistocene of the Shiobara Group in Nasushiobara, Tochigi, Japan. The fossil was identified as Bombus (Megabombus) cf. diversus Smith, 1869, a species distributed throughout Japan. The fossil is large, with an estimated total body length of 24 mm. The new specimen is the first bumblebee fossil from the Middle Pleistocene, the most geologically recent occurrence of a bumblebee fossil, and the first fossil of an extant bumblebee species. This discovery suggests that modern bumblebee species originated between the Pliocene and Middle Pleistocene. This new fossil is a valuable resource for studying bumblebee speciation.

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.

ZooBank registration: urn:lsid:zoobank.org:pub:35693991-2F1D-414C-96EF-487CD8FBF96C

Pseudovertagus canudai sp. nov. is described on the basis of a single specimen from the Pleistocene Tuktuk Formation in Leyte, Philippines. This represents the second extinct species of Pseudovertagus. Pseudovertagus canudai sp. nov. most closely resembles the rare living species Pseudovertagus phylarchus but can be distinguished by its smaller shell, the presence of finely incised spiral grooves on the last three whorls, and the slightly prosoclinal axial ribs on the early spire whorls. The shell bears rounded pits, which were most likely excavated by the co-occurring hipponicid gastropod Sabia while it was occupied by a hermit crab. This is the second fossil example of a Sabia-hermit crab association from an offshore soft-bottom environment.

ZooBank registration: urn:lsid:zoobank.org:pub:1DAECF2A-8B12-43D5-BD47-14F7F915F787

A tarsometatarsus belonging to the family Plotopteridae (Aves, Suliformes) is described from the lower Oligocene Yamaga Formation of the Ashiya Group on the island Ainoshima in Kitakyushu, Fukuoka, western Japan. It resembles Phocavis in gracility and size but shares with Copepteryx and Hokkaidornis features such as an elongated trochlea metatarsi IV, splayed trochlea metatarsi II, and an intertrochlear fossa between the trochleae metatarsorum III and IV. Comparison with modern waterbirds indicates that the intertrochlear fossa represents an ancestral character. Intertrochlear structures exhibit variability among plotopterids, suggesting that these structures underwent distinct evolutionary modifications within each lineage. The specimen does not appear to be a referable to Copepteryx or Hokkaidornis, implying a greater morphological diversity of the family in Japan.

The lower jaws of two pachydiscid ammonites, Menuites japonicus (Matsumoto) and Eupachydiscus sp., are described based on two specimens from the Coniacian to Santonian (Upper Cretaceous) strata of the Haboro and Mikasa areas in Hokkaido, Japan. They are preserved in situ in the body chamber and exhibit features intermediate between the lower jaws of anaptychus and aptychus types, specifically, a broadly open outer lamella composed of inner “chitinous” and outer calcareous layers, a flat rostrum, and a median furrow along the hood ridge of the inner layer. These characteristics have also been documented in the lower jaws of other previously described pachydiscid species, suggesting they are diagnostic of the family. The unusually large, shovel-shaped lower jaws with flat rostral margins may have evolved in relation to a microphagous feeding strategy. Additionally, the ventral outline of the lower jaw roughly matches the cross-sectional outline of shell aperture, although the former is smaller than the latter. As previously supposed in some Jurassic ammonoids, Late Cretaceous pachydiscids were presumably able to withdraw their soft parts deep into the body chamber, thereby avoiding being eaten by predators. Under such circumstances, their widely open lower jaws could have an operculum-like role to protect the retracted soft body from predator’s attack.

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.

Intraspecific variation of Neogastroplites muelleri Reeside and Cobban throughout ontogeny was studied based on 100 well-preserved specimens ranging in diameter from 10 to 75 mm that were extracted from a single calcareous concretion in the Mowry Shale Formation of the Colorado Group (lower Cenomanian) in central Montana, USA. The embryonic shell is exceptionally large among Ammonitina, and the width of the initial chamber exhibits a wide range of intraspecific variation in relation to its diameter, and thus a large variation exists in the thickness of the initial chamber. There is a positive correlation during the post-hatching stage between shell growth ratios (whorl width to whorl height and umbilical diameter to shell diameter) and relative initial chamber thickness, such that those specimens with more depressed initial chambers have greater growth ratios than those that are more compressed. This may imply that the initial chamber morphology could constrain subsequent shell growth. Due to the differences in these growth ratios, the degree of intraspecific variation of relative whorl thickness and relative umbilical size increases as the shell grows. Our analysis suggests that this high level of intraspecific variation in N. muelleri is directly related to the large morphological differences observed in the initial chambers, and these corresponding differences are maintained in the shell growth ratios of the subsequent post-hatching stages. The large embryonic shell suggests that the inhospitable environment of the Mowry Sea may have reduced the survival of newly hatched ammonoids, thus allowing Neogastroplites to survive by evolving a larger hatching size. Although the cause of the large variation observed in the relative initial chamber thickness is unclear, the wide intraspecific variation observed in post-hatching shell morphology implies that the physical and biological environment did not reduce the survival of individuals with different shell morphologies. This observation suggests that the Mowry Sea may have been an environment lacking external constraints for post-hatching Neogastroplites, when compared to other post-hatching environments.

Dentognathic fossil specimens of a Galerella-like small mongoose (Mammalia, Carnivora, Herpestidae) are described from the basal upper Miocene (ca. 10 Ma; Tortonian) Nakali Formation of central Kenya. They show comparable dental morphology to extant Herpestes, Xenogale, Galerella, and Urva: a better-developed parastylar shelf than the metastylar region on upper first molar (M1), an absence of the metastyle on M1, a trenchant and enlarged trigonid with a well-developed prevalid (mesial shearing blade) on lower first molar (m1), and much smaller m2 compared to m1. Compared with fossil “Herpestes”-like genera, the Nakali specimens are distinguished from them: they differ from Herpestides in being smaller and in having a much less developed cingulum on M1; from Leptoplesictis, Dunictis, and Forsythictis in having a less mesially-protruded paraconid (less mesiodistally-elongated prevalid) on m1; from Ugandictis and Kichechia in having a better-developed prevalid on m1, a much smaller m1 talonid, and much smaller m2 compared to m1. Taking the very small size into account, the Nakali specimens are more comparable to Galerella and very small species of Urva rather than to Herpestes, Xenogale, and larger species of Urva. The Nakali specimens are more comparable to very small Urva than to Galerella in the retention of small and single-rooted lower first premolar (p1). However, although extant Galerella generally lacks p1, several specimens of extant Galerella retain it. It is noteworthy that Galerella is an African genus, while Urva is an Asian genus. Here, we identified the Nakali specimens as cf. Galerella sp. because they are from Africa, but it should be noted that there is a possibility that they are of Urva or of unknown extinct lineage. This study highlights the problem of the taxonomic identification of fossil dentognathic specimens that were identified as “Herpestes.”

Pistocythereis bradyi and Pistocythereis bradyformis are trachyleberidid ostracods that have been abundant in the inner bays of East Asia since the Pliocene. In this study, we described the appendages of the two Pistocythereis species and investigated the changes in shell traits throughout ontogeny in both species. Although the morphological characters seen on the inside of the shell, such as hinge, ocular sinus, marginal spine and duplicature, are common to both species, there were inter- and intraspecific variations in the external surface ornamentation. The variation in traits visible on the outside of the shell is thought to be due to functional requirements, such as protecting fragile setae.

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).