Sato, T., Konishi, T., Nishimura, T. and Yoshimura, T., in press: A basal mosasauroid from the Campanian (Upper Cretaceous) of Hokkaido, northern Japan. Paleontological Research. doi:10.2517/2017PR018. オンライン公開日2017年09月13日. PDF
A basal mosasauroid specimen, including a rib and a vertebra from middle to posterior portion of the trunk, is reported from the lower Campanian Inoceramus (Platyceramus) japonicus zone in Obira Town, northern Hokkaido, northern Japan. It is the second occurrence of basal mosasauroids sensu lato in Japan after the halisaurine Phosphorosaurus ponpetelegans, but represents a larger individual than the P. ponpetelegans holotype. The Obira specimen predates the early Maastrichtian P. ponpetelegans by about 10 million years, indicating colonization by basal mosasauroids of the northwestern Pacific by at latest the early Campanian age. While the overall morphology of the Obira specimen agrees well with that of a halisaurine vertebra, the presence of well-developed zygantra (zygosphenes missing postmortem if present) on the vertebra and its inclined condyle uniquely align the specimen with Pannoniasaurus inexpectatus, a Santonian-aged basal mosasauroid from freshwater deposits in Hungary.
Yamada, in press: Plant fossils from the Arimine Formation (Oxfordian, Jurassic) of the Tetori Group in Arimine, Toyama Prefecture, Central Japan. Paleontological Research. doi:10.2517/2017PR017. オンライン公開日2017年08月27日. PDF
Ptilophyllum sp. and Zamites brevipennis are newly described from the middle Oxfordian Arimine Formation in Arimine area, Toyama Prefecture, Central Japan. These two species characterize the vegetation of the Eurosinian paleophytogeographic province where a climate with dry season(s) prevailed. This finding, as well as the presence of a Kaizara Flora, suggests that Eurosinian-type vegetations continuously flourished during the late Bathonian to Oxfordian on the land of the Tetori Group. We also infer that Tetori-type floras first appeared during the Tithonian in the Tetori Group.
Jenkins, R. G., Kaim, A., Amano, K., Sakurai, K. and Matsubara, K., in press: A new Miocene whale-fall community dominated by bathymodiolin mussel Adipicola from Hobetsu area, Hokkaido, Japan. Paleontological Research. doi:10.2517/2017PR006. オンライン公開日2017年06月23日. PDF
We report the fourth record of a fossil whale-fall community in Japan. The new material consists of a single whale bone associated mainly by small bathymodiolin mussels, Adipicola sp., found in the Karumai Formation (late middle Miocene–early late Miocene) in the Hobetsu area of Hokkaido, Japan. This association of whale bone and Adipicola sp. and its mode of occurrence resembles the description of some other ancient whale-fall communities dominated by small mussels from the Olympic Peninsula in Washington State (early Oligocene), Shosanbetsu in Hokkaido (early middle Miocene) and Carpineti in northern Italy (middle Miocene) and constitutes an example of a chemosynthesis-based community sustained by whale–fall decay in the Miocene deep sea. The new example extends the Miocene distribution of bathymodiolin dominated whale-fall communities to the northwestern Pacific Ocean.
Wang, Y. and Wang, Y., in press: Globusphyton Wang et al., an Ediacaran macroalga, crept on seafloor in the Yangtze Block, South China. Paleontological Research. doi:10.2517/2017PR005.. オンライン公開日2017年06月21日. PDF
The Ediacaran genus Globusphyton Wang et al., only including one species G. lineare Wang et al., is a eukaryotic macroalga in the Wenghui biota from black shale of the upper Doushantuo Formation (ca. 560–551 Ma) in northeastern Guizhou, South China. It was assigned as one of significant fossils in the assemblage and biozone divisions in the middle-late Ediacaran Period. Morphologically, Globusphyton is composed of several structural components, displaying that it had tissue differentiation to serve various bio-functions. Its prostrate stolon, a long ribbon bundled by unbranching filaments, crept by holdfasts on the seafloor. Its pompon-like thalli, the circular to oval thallus-tuft composed of many filamentous dichotomies, may have served for photosynthesis. The fusiform ribbon-tubers, the caked and expanded segments of the ribbon, may have served to sustain the growth of the thalli and the possible holdfasts. The zigzag-shaped stolon and pompon-like thalli of Globusphyton, in a relatively low-energy environment,were crept on the surface of the muddy sediments and suspended in water column, respectively. When water current occurred occasionally, all or part of its body was probably suspended in the water column to be deformed as a variable pattern.
Kuwahara, K. and Sano, H., in press: Upper Middle to lower Upper Permian latentifistularian (Radiolaria) interval zones of the Mino Belt in the Mt. Funabuseyama area, central Japan. Paleontological Research. doi:10.2517/2017PR004. オンライン公開日2017年02月15日. PDF
We present a biostratigraphic study of the Latentifistularia (Radiolaria) in the upper Middle to lower Upper Permian (upper Capitanian to lower Wuchiapingian) succession of bedded chert of the Mino Belt in the Mt. Funabuseyama area, central Japan. The rocks examined are interpreted to be of pelagic facies on the deep-marine lower flank of a mid-Panthalassic seamount. We established six, latentifistularian-based interval zones in the chert succession (ca. 12.5 m in thickness) by using the first appearance datum of the latentifistularian species. They are the Foremanhelena triangula, Ruzhencevispongus sp. B, Ruzhencevispongus sp. C, Triplanospongos angustus, Cauletella paradoxa, and Triplanospongos musashiensis interval zones in ascending order. The first interval zone is underlain by an unnamed zone characterized by Follicucullus charveti and F. spp. with minor F. bipartitus and Pseudoalbaillella sp. On the basis of the radiolarian assemblage, we correlate the Foremanhelena triangula, Ruzhencevispongus sp. B, Ruzhencevispongus sp. C, Triplanospongos angustus interval zones and the Cauletella paradoxa and Triplanospongos musashiensis interval zones with the Follicucullus charveti-Albaillella yamakitai and Neoalbaillella ornithoformis assemblage zones in Japan, respectively. The lower three interval zones and the upper two interval zones are compared with the upper Capitanian and lower Wuchiapingian, respectively. The Triplanospongos angustus Interval Zone presumably includes the Guadalupian-Lopingian boundary. Our results show that the latentifistularians can be used to the biostratigraphic zonation of the upper Capitanian to lower Wuchiapingian stages, in which the albaillellarians are much less abundant and diverse. The newly proposed interval zones permit the further subdivision of upper Capitanian to lower Wuchiapingian successions.
Uchimura, H., Nishi, H., Takashima, R., Kuroyanagi, A., Yamamoto, Y. and Kutterol, S., in press: Distribution of recent benthic f 2 oraminifera off western Costa Rica in the eastern equatorial Pacific Ocean. Paleontological Research. doi:10.2517/2017PR003. オンライン公開日2017年02月15日. PDF
Benthic foraminifera provide essential information for paleobathymetric reconstructions. However, the modern distribution of benthic foraminifera, especially at depths below 1000 mbsl, is still obscure in the offshore regions near Central and South America. To characterize the bathymetric scale in the eastern equatorial Pacific Ocean, we examined the depth distribution of benthic foraminifera using piston core samples taken off the coast of Costa Rica. Foraminiferal assemblages vary according to water depth: 1) U1 (mainly composed of Ammonia beccarii, Cancris sagra, Elphidium tumidum, Hanzawaia concentrica, Pseudononion basispinata, and Planulina exorna) represent inner shelf faunas (shallower than 50 mbsl). 2) U2 (mainly composed of Ammobacculites foliaceu, Bolivina striatula, Cassidulina minuta, Hanzawaia concentrica, Uvigerina incilis, Bulimina denudata, and Cancris sagra) is correlated with mid shelf depth assemblages, from 50 to 100 mbsl. 3) U3 (mainly composed of Uvigerina incilis, Hanzawaia concentrica, Angulogerina semitrigona, Bolivina acuminata, Bolivina bicostata, and Cibicorbis inflatus) is assigned to outer shelf assemblages from 100 to 200 mbsl. 4) U4 (mainly composed of Bolivina humilis, Bolivina seminuda, Bolivina subadvena, Cassidulina tumida, Epistominella obesa, Angulogerina carinata, and Cibicorbis inflatus) is the upper bathyal faunas (200–600 mbsl). 5) U5 (mainly composed of Brizalina argentea, Uvigerina peregrina, Uvigerina auberiana, Brizalina seminuda, Bulimina striata, Epistominella smithi and Globocassidulina subglobosa) is the mid bathyal faunas (600–1000 mbsl). 6) U6 (mainly composed of Uvigerina auberiana, Uvigerina peregrina, Brizalina argentea, Bulimina mexicana, Cassidulina carinata, Epistominella smithi, and Lenticulina cushmani) represent the lower bathyal assemblage (1000–2000 mbsl). 7) U7 (mainly composed of Uvigerina auberiana, Brizalina argentea, and Eubuliminella tenuata) represent upper abyssal faunas (2000-3000 mbsl). 8) U8 (mainly composed of Glomospira sp.A, Lagenammina arenulata, Chilostomella oolina, Hoeglundina elegans, Melonis barleeanum, Nonion affine, Oridorsalis umbonatus, Pullenia bulloides, and Uvigerina proboscidea) is characterized by deep-water cosmopolitan faunas (deeper than 3000 mbsl). On the basis of a comparison with several environmental parameters, dissolved oxygen concentrations are likely to be the most effective factor controlling foraminiferal depth distributions in the eastern equatorial Pacific especially the below oxygen minimum zone (OMZ). Around OMZ, nitrate concentration also might be related with the benthic assemblage due to the nitrate respiration.
Kamikuri, S., Itaki, T., Motoyama, I. and Matsuzaki, K. M., in press: Radiolarian biostratigraphy from middle Miocene to late Pleistocene in the Japan Sea. Paleontological Research. doi:10.2517/2017PR001. オンライン公開日2017年02月15日. PDF
In the Integrated Ocean Drilling Program (IODP) Exp. 346, sampling by drilling was conducted at seven sites (U1422–U1427 and U1430) in the Japan Sea. Radiolarians in moderately well preserved states were found in most samples throughout the sequence in varying abundance. Forty-one radiolarian datum events were identified in this study, and the radiolarian zonation that best divides the middle Miocene to Pleistocene sequences with updated ages of radiolarian datum events (estimates based on the geomagnetic polarity time scale (GTS) 2012) was applied to the sedimentary sequences in the Japan Sea. Here, four new radiolarian zones are proposed for the Quaternary of the Japan Sea, and one zone is slightly revised to adjust for differences among other zones. The sequences collected at the sites extended from the Pleistocene Ceratospyris borealis Zone to progressively deeper zones as follows: Site U1427, four zones to the Pleistocene Schizodiscus japonicus; Site U1422, six zones to the late Pliocene Hexacontium parviakitaense Zone; Sites U1423, U1424 and U1426, eight zones to the early Pliocene Larcopyle pylomaticus Zone; and Sites U1425 and U1430, fourteen zones to the middle Miocene Eucyrtidium inflatum Zone. The absence or extremely rare occurrence of Stylatractus universus and E. matuyamai indicates that S. universus lived in the deep water of the northwestern Pacific and had not been able to migrate into the Japan Sea across the Tsugaru Strait since the Pliocene.
Tsubamoto, T., Kunimatsu, Y., Sakai, T., Saneyoshi, M., Shimizu, D., Morimoto, N., Nakaya, H. and Nakatsukasa, M., in press: Listriodontine suid and tragulid artiodactyls (Mammalia) from the upper Miocene Nakali Formation, Kenya. Paleontological Research. doi:10.2517/ 2016PR034. オンライン公開日2016年12月15日. PDF
Two rare artiodactyl mammals from the basal upper Miocene Nakali Formation (ca. 10 Ma) of central Kenya are described. They are cf. Listriodon sp. (Suidae, Listriodontinae) and Dorcatherium cf. pigotti (Ruminantia, Tragulidae), which are the first discoveries of a listriodontine and a tragulid in the formation. Cf. Listriodon sp. is represented by a talonid of a lower molar that has a strongly lophodont hypolophid. Although this listriodontine material is fragmentary, it is comparable in morphology and size to large and fully lophodont species of the genus Listriodon, such as L. splendens and L. pentapotamiae theobaldi. If the Nakali specimen proves to be phyletically closely related to these two species, it indicates that a highly derived lineage of Listriodon existed in East Africa around 10 Ma, implying a possible migration of this lineage from Europe/Asia to East Africa during the middle or earliest late Miocene. Dorcatherium cf. pigotti is represented by DP4 (or M1) and a mandible with p3–m3, which are comparable in size to those of D. pigotti among the African species of the genus. Although the genus Dorcatherium and species D. pigotti are common taxa in the early to middle Miocene of Africa, they are rarely found in the late Miocene. This is the second record of the genus in the late Miocene of Africa, reinforcing evidence that Dorcatherium existed until the basal late Miocene in East Africa.
Tazawa, J., in press: An early Carboniferous (late Visean) brachiopod fauna from Tairagai in the Yokota area, South Kitakami Belt, Japan. Paleontological Research. doi:10.2517/ 2016PR033. オンライン公開日2016年12月15日. PDF
In this paper, a brachiopod fauna (the Tairagai fauna), consisting of 11 species in 11 genera, is described from the uppermost part of the Odaira Formation at Tairagai in the Yokota area, South Kitakami Belt, northeastern Japan. The age of the fauna is identified as the late Visean (early Carboniferous). Palaeobiogeographically, the Tairagai fauna has a close affinity with those of western Europe (the UK, Germany and Belgium), central Russia (southern Urals and Kuznetsk Basin), Kazakhstan, Kirgiz and northwestern China (Xinjiang and Gansu). The South Kitakami region probably located near the North China block in the Late Palaeozoic, and tectonically belongs to the CAOB.
Yabe, A., in press: Revision of Cunninghamia protokonishii Tanai et Onoe (Pinopsida, Cupressaceae) from East Asia. Paleontological Research. doi:10.2517/ 2016PR032. オンライン公開日2016年12月15日. PDF
Morphological and cuticular features of Cunninghamia protokonishii were examined, studying the original material and additional fossils that were collected from the earliest Miocene to the early Pleistocene of Japan and Korea. The species is characterized by foliar morphology that superficially resembles C. konishii, but differs by large terminal seed cones and seeds, which are more similar to C. lanceolata. Cuticle of C. protokonishii shows a wide range of anatomical variability compared to the extant two species that include epidermal cell size, stomata distribution, and orientation. Based on foliar morphology, C. protokonishii can be distinguished from all other known fossil and extant species of Cunninghamia described so far. Distribution of C. protokonishii was mostly confined to the Japanese islands, with neighboring areas in Korea and southern Sakhalin. It appeared in eastern Asia by the earliest Miocene—a time prior to the opening of the Sea of Japan—and persisted until the Mio-Pliocene on the Japanese islands.
Takahashi, Y., Sutou, M., and Yamamoto, S., in press: The compression mating fossil of sciarid fly (Diptera: Sciaridae) from Shiobara, Tochigi Prefecture, Japan. Paleontological Research. doi:10.2517/2016PR031. オンライン公開日2016年12月15日. PDF
Preservations illustrating insect reproductive behaviors are much rarer in compression fossils than in amber. We discovered a copulating compression fossil of the sciarid flies from the Pleistocene Shiobara Group, Tochigi Prefecture, Japan, which is briefly described herein. The specimen represents one of the rare examples of a compression fossil showing mating dipteran insects. This finding implies that the small bodies of sciarid flies which readily fall onto the water surface may have contributed to the preservation of our copulating fossil. Moreover, the depositional environment of the paleo-Shiobara Lake was the main factor that served to preserve this specimen.
Mori, H., Marx, F. G., Kohno, N., Nakaya, H. and Anazaki, H., in press: Enigmatic humerus of an archaic Oligocene-Miocene neocete from Miyazaki Prefecture, Kyushu, Japan. Paleontological Research. doi:10.2517/2016PR026. オンライン公開日2016年11月11日. PDF
Rathore, A. S., Grover, P. Verma, V., Lourembam, R. S. and Prasad, V. R., in press: Late Cretaceous (Maastrichtian) non-marine ostracod fauna from Khar, a new intertrappean locality, Khargaon district, Madhya Pradesh, India. Paleontological Research. doi:10.2517/ 2016PR025. オンライン公開日2016年11月11日. PDF
Tazawa, J. and Araki, H., in press: Middle Permian (Wordian) mixed Boreal‒Tethyan brachiopod fauna from Matsukawa, South Kitakami Belt, Japan. Paleontological Research. doi:10.2517/2016PR029. オンライン公開日2016年11月07日. PDF
Kamikuri, S., in press: Late Neogene radiolarian biostratigraphy of the eastern North Pacific ODP Sites 1020/1021. Paleontological Research. doi:10.2517/ 2016PR027. オンライン公開日2016年11月07日. PDF