Pollen assemblage from the paleoparadoxiid whole skeleton (“Mizunami-Kamado specimen”) bearing-sediments of the Miocene Mizunami Group, Gifu Prefecture, Japan

Paleovegetational reconstruction based on pollen assemblages from the Tokiguchi Porcerlain Clay Formation (Miocene), Gifu Prefecture, Japan

A Late Cretaceous ammonoid Polyptychoceras and an assemblage of fossil spores and pollen from Neo Village, Gifu Prefecture, central Japan

A platanistoid fossil was recovered from the upper Lower Miocene Akeyo Formation, Mizunami Group, Gifu Prefecture, Japan. It consists of a right scapula, two cervical and three thoracic vertebrae, and an isolated tooth. The following key apomorphies of Platanistoidea are found in the scapula of the specimen: loss of or greatly reduced coracoids process, acromion located on the anterior edge of the scapula, and disappearance of the supraspinatus fossa on the lateral side of the scapula. This is the fourth platanistoid to be reported from Japan.

ABSTRACTA new early Miocene large castorid, Minocastor godai gen. et sp. nov., from the Dota locality, Gifu Prefecture in central Japan, is described on the basis of dentaries and teeth. The material comes from the Kani basin, where limnofluviatile clay and sandstones of the Nakamura Formation (Mizunami Group) are exposed on the southern (left) bank of the Kiso River. It represents the richest sample of a Miocene small mammal in the Japanese fossil record thus far known. Based on jaw and tooth morphology, this new castorid most likely represents a primitive anchitheriomyine. However, it lacks the marked striations on the incisors that are characteristic of the advanced large, middle Miocene anchitheriomyines like Anchitheriomys and Amblycastor. The new castorid shares this dental feature with other primitive anchitheriomyines from Asia and North America, like Propalaeocastor, Oligotheriomys, and Miotheriomys. For these genera, a new tribe, Minocastorini, is proposed as sister group to the Anchitheriomyini. The incisor enamel microstructure of the new castorid largely exhibits plesiomorphic characters but also apomorphic features such as pseudo-pauciserial Hunter-Schreger bands. Additionally, the outer portion of the enamel band is rather thick in comparison to that of other beavers. Based on the rodent taxa associated with Minocastor godai gen. et sp. nov., Dota can be correlated with European Neogene mammal units MN 3/4. Magnetostratigraphic studies and radiometric dates obtained from the Mizunami Group indicate that Dota is more likely correlated with MN 3, with an absolute age of around 18.5 Ma.http://zoobank.org/urn:lsid:zoobank:org:pub:B1886424-1759-4BDA-A5CC-D122436E1A76 Citation for this article: Mörs, T., Y. Tomida, and D. C. Kalthoff. 2016. A new large beaver (Mammalia, Castoridae) from the early Miocene of Japan. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1080720.

The stratigraphic succession of the Cenozoic strata developed in the Iwamura basin is as follows; Age Terrace deposits unconformity Hirooka gravel Tazawa sand and gravel I2 Seto group Higashihora formation H2 Mizunami group Toyama formation Agi formation F2∼F3 unconformity and fault Granite and Quartz-porphyry The Mizunami group represents a cycle of sedimentation and its lower part or the Agi formation may be freshwater in origin while the upper or Toyama formation, which consists of five members is marine., The Mizunami group is probably middle Miocene (F2∼F3) in age as inferred from the molluscan fossils., It forms a synclinal structure controlled by the fault of NE-WS trend.,

The Tono Mine, Gifu Prefecture is one of the richest sedimentary uranium deposits in Japan. This areas is mainly composed of Tertiary system overlying granite basement. Uranium has been deposited in the lower part of the Tertiary sediments, Mizunami Group, and its location is controlled by the socalled channel structure of the surface of the basement granites. The matrixes of these sediments usually contain tuffaceous materials, which have been argillized and zeolitized diagenetically, and uranium was absorbed in clinoptilolite. The clay mineral species and their relative amounts are closely related to the redox potential and hydrogen ion concentration of the deposits, which are controlled by the movement of groundwater. Main authigenic minerals are montmorillonite, kaolinite, halloysite, sericite and clinoptilolite. In an S-N gallery, the amount of montmorillonite regularly decreases with increasing amount of kaolin minerals and uranium contents. Some iron minerals and calcium minerals are closely associated with clay minerals, zeolite and uranium contents, so the stability relation of their minerals and mineral paragenesis suggest the environments of alteration in this area.

岐阜県瑞浪層群明世累層“宿洞砂岩相”（中新統）からのマングローブ植物花粉の発見

Citation for this article: Handa, N., and S. Kawabe. 2016. Femur of Schizotheriinae (Perissodactyla, Chalicotheriidae) from the lower Miocene Hiramaki Formation of the Mizunami Group in Gifu Prefecture, central Japan. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1131163.

市道戸狩・月吉線工事現場(瑞浪市明世町)の下部中新統瑞浪層群明世層より鰭脚類の頭蓋を含む骨格化石の産出

Marine paleoclimatological reappraisal of molluscan fauna of the Early Miocene Akeyo Formation, Mizunami Group, Gifu Prefecture

Some Miocene boring Shells and their life tracks ("Lebens-spuren") from the Mizunami group, Gifu Prefecture, Japan

Miocene molluscan fossils from the Akeyo Formation, Mizunami Group at the outcrop exposed during construction of Togari-Tsukiyoshi City Road in Mizunami City, Gifu Prefecture, Japan

Abstract. The Tsukiyoshi uranium deposit in Gifu Prefecture is the largest one in Japan. It is embedded in lower part of the Mizunami Group of Miocene age. Relating to the existence of this uranium deposit, the constituent minerals in sediments were studied by XRD and SEM, using many drilling cores. The most abundant authigenic mineral is smectite. The amount of smectite increases generally from upper to lower horizons, and a highly smectitized zone is situated around the uranium deposit. Smectitization predominated in mafic glassy grains of sediments, which was probably formed in early burial diagenesis. Zeolites including clinoptilolite‐heulandite, mordenite, analcime, chabazite and philipsite are secondly abundant authigenic minerals. They seem to have been formed at early to late diagenetic stages. Opaline silica is rather rare. Carbonate minerals, including cal‐cite, dolomite, siderite and rhodochrosite are common. They may be formed by diagenesis as well. Gypsum and pyrite occur in upper horizons and lower horizons, respectively. In particular, a highly smectitized zone including pyrite probably played an important role for retarding the migration of uranium and as a result keeping the uranium deposit for past one million years. This smectite‐zeolite envelope surrounding the Tsukiyoshi uranium deposit is regarded as a natural analogue of the buffer materials surrounding the high‐level radioactive waste repository.

A new species of the genus Amia of the family Amiidae, A. godai is described based on a parasphenoid and many isolated bones and scales found from the Early Miocene Nakamura Formation of the Mizunami Group along the Kiso River in Kani City, Gifu Prefecture, Central Japan. Amia godai sp. nov. is distinguished by having a V-shaped edentulous area in the posterior part of the tooth patch of the parasphenoid. This is the first record of the genus from the Early Miocene in the world and the first record of the family from the Cenozoic in Japan.

Limnobiophyllum expansum (Lemnoideae, Araceae) was newly found in the lower Miocene (18.4–17.0 Ma) Hiramaki Formation of the Mizunami Group in the Kani Basin, Gifu Prefecture, central Japan. This genus was distributed widely in the Northern Hemisphere from the Late Cretaceous to the Paleocene, but a Miocene descendant (L. expansum) was reported only from Europe, in the Bohemian Basin, Czech Republic (early Miocene), Paldau, Austria (late Miocene), Schrotzburg, Switzerland (late Miocene) and Sośnica, Poland (late Miocene). Our finding is the first record of a Miocene Limnobiophyllum from an area other than Europe. The aquatic flora of Japan during the early Miocene is poorly documented, but this finding suggests a link between the aquatic floras of Europe and Asia.