Y. Ishida, Minoru Kaneko, Asaka Yokobori, Rin Mita, Hiroyuki Ishikawa, B. Thuy, Lea D. Numberger-Thuy, T. Fujita
Abstract. Over 100 well-preserved dissociated ophiuroid arm ossicles, i.e., lateral arm plates, dorsal arm plates, ventral arm plates, vertebrae and arm spines, were recovered from the upper Pleistocene Kioroshi Formation in the core of borehole GS-NY-1 at Nagareyama, Chiba Prefecture, central Japan. Following comparison with the lateral arm plates of ten extant amphiurid species occurring in the seas around Japan and with previously published fossil taxa in this family, the ossicles from Nagareyama were identified as belonging to the extant species, Amphiura multispina. This is the first fossil record of this form and the stratigraphically youngest of the Amphiuridae. The taphonomy and paleoenvironment of the brittle star fossils described are also discussed.
{"title":"Amphiura multispina (Ophiuroidea, Amphiuridae) from the Upper Pleistocene Kioroshi Formation in a Drill Core at Nagareyama, Chiba, Central Japan","authors":"Y. Ishida, Minoru Kaneko, Asaka Yokobori, Rin Mita, Hiroyuki Ishikawa, B. Thuy, Lea D. Numberger-Thuy, T. Fujita","doi":"10.2517/PR220001","DOIUrl":"https://doi.org/10.2517/PR220001","url":null,"abstract":"Abstract. Over 100 well-preserved dissociated ophiuroid arm ossicles, i.e., lateral arm plates, dorsal arm plates, ventral arm plates, vertebrae and arm spines, were recovered from the upper Pleistocene Kioroshi Formation in the core of borehole GS-NY-1 at Nagareyama, Chiba Prefecture, central Japan. Following comparison with the lateral arm plates of ten extant amphiurid species occurring in the seas around Japan and with previously published fossil taxa in this family, the ossicles from Nagareyama were identified as belonging to the extant species, Amphiura multispina. This is the first fossil record of this form and the stratigraphically youngest of the Amphiuridae. The taphonomy and paleoenvironment of the brittle star fossils described are also discussed.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"310 - 323"},"PeriodicalIF":0.9,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41824982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Conglomerate of the Lower Jurassic Kuruma Group contains microfossil-bearing clasts. In the present study, these microfossils were investigated via the hydrofluoric acid (HF)-etched surfaces of the clasts and residues produced during acid treatment. As a result, Permian (mainly Guadalupian–Lopingian) radiolarians were obtained from mudstone and chert clasts; spicules of indeterminate age were obtained from the chert clasts. The mudstone clasts were derivable from the Akiyoshi, Ultra-Tamba, Maizuru, and/or Hida-Gaien belts or equivalent units, while the spicule-dominated chert clasts likely originated from the Akiyoshi belt or equivalent units. Except for tuff and acidic volcanic rocks, the clast components of the Kuruma Group in this study are similar to the component rocks of the Akiyoshi belt.
{"title":"Permian Radiolarians and Spicules from Conglomerate of the Lower Jurassic Kuruma Group in Itoigawa, Niigata Prefecture, Central Japan","authors":"Tsuyoshi Ito, Takuma Kawajiri, A. Matsuoka","doi":"10.2517/PR220005","DOIUrl":"https://doi.org/10.2517/PR220005","url":null,"abstract":"Abstract. Conglomerate of the Lower Jurassic Kuruma Group contains microfossil-bearing clasts. In the present study, these microfossils were investigated via the hydrofluoric acid (HF)-etched surfaces of the clasts and residues produced during acid treatment. As a result, Permian (mainly Guadalupian–Lopingian) radiolarians were obtained from mudstone and chert clasts; spicules of indeterminate age were obtained from the chert clasts. The mudstone clasts were derivable from the Akiyoshi, Ultra-Tamba, Maizuru, and/or Hida-Gaien belts or equivalent units, while the spicule-dominated chert clasts likely originated from the Akiyoshi belt or equivalent units. Except for tuff and acidic volcanic rocks, the clast components of the Kuruma Group in this study are similar to the component rocks of the Akiyoshi belt.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"359 - 374"},"PeriodicalIF":0.9,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41617800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ayano Mizukami, R. Matsumoto, Ryoji Wani, S. Evans
Abstract. The Early Cretaceous Kuwajima Formation, Tetori Group, Japan has yielded various aquatic and terrestrial vertebrates, but lissamphibian records are limited to albanerpetontids and an isolated longbone of a frog. Here we provide the first report of an associated frog specimen from the Tetori Group. The specimen is composed of a few skull elements and several postcranial bones, including the femur, ilium, and vertebrae. This new Tetori frog is distinguished from the previously reported Early Cretaceous Asian genera, Liaobatrachus from China, and Hyogobatrachus and Tambabatrachus from Japan, in having hatchet-shaped sacral diapophyses and a posteriorly tapering urostyle with a weakly developed dorsal crest. Phylogenetic analysis of this new material places it as a non-neobatrachian frog that may be related to previously described Chinese and Japanese taxa, but more complete material would be needed to establish its affinities with confidence.
{"title":"A Three-Dimensionally Preserved Frog (Amphibia, Anura) from the Lower Cretaceous Kuwajima Formation, Tetori Group, Ishikawa Prefecture, Japan","authors":"Ayano Mizukami, R. Matsumoto, Ryoji Wani, S. Evans","doi":"10.2517/PR210031","DOIUrl":"https://doi.org/10.2517/PR210031","url":null,"abstract":"Abstract. The Early Cretaceous Kuwajima Formation, Tetori Group, Japan has yielded various aquatic and terrestrial vertebrates, but lissamphibian records are limited to albanerpetontids and an isolated longbone of a frog. Here we provide the first report of an associated frog specimen from the Tetori Group. The specimen is composed of a few skull elements and several postcranial bones, including the femur, ilium, and vertebrae. This new Tetori frog is distinguished from the previously reported Early Cretaceous Asian genera, Liaobatrachus from China, and Hyogobatrachus and Tambabatrachus from Japan, in having hatchet-shaped sacral diapophyses and a posteriorly tapering urostyle with a weakly developed dorsal crest. Phylogenetic analysis of this new material places it as a non-neobatrachian frog that may be related to previously described Chinese and Japanese taxa, but more complete material would be needed to establish its affinities with confidence.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"333 - 349"},"PeriodicalIF":0.9,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46159992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The Moscovian part of the Ichinotani Formation is subdivided into six fusuline zones from lower to upper, Fusulinella kamitakarensis, Fusulina? sp., Fusulinella hanzawai–Fusulina kamensis, Fusulinella rhomboidalis–Protriticites ovatus, Beedeina lanceolata, and Fusulinella rhomboidalis–Fusulinella soligalichi. The strata underlying the first zone, previously assigned to the Moscovian, are reassigned to the upper part of the Bashkirian. Age-diagnostic species are scarce in the possibly Kashirian F. kamitakarensis Zone and are absent in the F.? sp. Zone. The third to the sixth zones are correlated to the Podolskian, Myachkovian, Podolskian, and Myachkovian of the stratotypes in the Russian Platform, respectively. The fourth zone is inferred to be fault bounded with the fifth zone. The sixth zone is overlain by the lower part of the Kasimovian Protriticites variabilis Zone. Twenty species of fusulines and five species of non-fusuline foraminifers are described. Newly proposed herein are Pseudojanischewskina titanica, Bradyinelloides paranautiliformis, and Fusulinella igoi.
{"title":"Moscovian (Middle Pennsylvanian) Foraminifers and Biostratigraphy of the Ichinotani Formation, Hida Marginal Terrane, Japan","authors":"F. Kobayashi","doi":"10.2517/PR210013","DOIUrl":"https://doi.org/10.2517/PR210013","url":null,"abstract":"Abstract. The Moscovian part of the Ichinotani Formation is subdivided into six fusuline zones from lower to upper, Fusulinella kamitakarensis, Fusulina? sp., Fusulinella hanzawai–Fusulina kamensis, Fusulinella rhomboidalis–Protriticites ovatus, Beedeina lanceolata, and Fusulinella rhomboidalis–Fusulinella soligalichi. The strata underlying the first zone, previously assigned to the Moscovian, are reassigned to the upper part of the Bashkirian. Age-diagnostic species are scarce in the possibly Kashirian F. kamitakarensis Zone and are absent in the F.? sp. Zone. The third to the sixth zones are correlated to the Podolskian, Myachkovian, Podolskian, and Myachkovian of the stratotypes in the Russian Platform, respectively. The fourth zone is inferred to be fault bounded with the fifth zone. The sixth zone is overlain by the lower part of the Kasimovian Protriticites variabilis Zone. Twenty species of fusulines and five species of non-fusuline foraminifers are described. Newly proposed herein are Pseudojanischewskina titanica, Bradyinelloides paranautiliformis, and Fusulinella igoi.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"160 - 181"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42683640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The origin and early dispersion of crown groups (e.g. Cervidae and Bovidae) in pecorans are traced back to the late Oligocene or early Miocene in Eurasia. The fossil pecorans from the lower Miocene of Japan are highly fragmentary but form evidence of a zoogeographic connection between Japan and the Eurasian continent during this period. In this study, we describe dental fossils (seven specimens) from five Burdigalian formations (Nakamura Fm. ∼18.5 Ma; Hiramaki Fm. ∼18 Ma; Misawa Fm. and Kitatage/Asakawa Fm. ∼17 Ma; Kunimi Fm. ∼16 Ma), and as a result of taxonomic revision we recognize four species, including a basal species of Cervidae, Dicrocerus? tokunagai, cf. Palaeomeryx minoensis, and Amphimoschus sp. These species have the basic occlusal patterns of cheek teeth inherited from primitive pecorans (e.g. Amphitragulus), but each species displays advanced characteristics, such as full selenodonty, a weak/no external postprotocristid, and a bicuspidate third lobe of m3 (Amphimoschus). The early group of crown pecorans composed of basal cervids (Lagomerycinae or Procervulinae), Palaeomeryx s.l., and Amphimoschus, had dispersed widely in Europe (early Orleanian or MN3) and East Asia (Shanwangian), including Japan. Our findings on the Japanese fossil records demonstrate that the dispersion of a basal cervid and palaeomerycid between Japan and the Eurasian continent had been completed before 18 Ma. Further studies with additional material would reveal detailed taxonomic relationships and evolutionary process of the Japanese pecorans in the Burdigalian.
{"title":"Taxonomic Revision of Lower Miocene Pecorans (Mammalia, Artiodactyla) from Japan, with a New Fossil Record of Stem Cervidae","authors":"Y. Nishioka, Y. Tomida","doi":"10.2517/PR210019","DOIUrl":"https://doi.org/10.2517/PR210019","url":null,"abstract":"Abstract. The origin and early dispersion of crown groups (e.g. Cervidae and Bovidae) in pecorans are traced back to the late Oligocene or early Miocene in Eurasia. The fossil pecorans from the lower Miocene of Japan are highly fragmentary but form evidence of a zoogeographic connection between Japan and the Eurasian continent during this period. In this study, we describe dental fossils (seven specimens) from five Burdigalian formations (Nakamura Fm. ∼18.5 Ma; Hiramaki Fm. ∼18 Ma; Misawa Fm. and Kitatage/Asakawa Fm. ∼17 Ma; Kunimi Fm. ∼16 Ma), and as a result of taxonomic revision we recognize four species, including a basal species of Cervidae, Dicrocerus? tokunagai, cf. Palaeomeryx minoensis, and Amphimoschus sp. These species have the basic occlusal patterns of cheek teeth inherited from primitive pecorans (e.g. Amphitragulus), but each species displays advanced characteristics, such as full selenodonty, a weak/no external postprotocristid, and a bicuspidate third lobe of m3 (Amphimoschus). The early group of crown pecorans composed of basal cervids (Lagomerycinae or Procervulinae), Palaeomeryx s.l., and Amphimoschus, had dispersed widely in Europe (early Orleanian or MN3) and East Asia (Shanwangian), including Japan. Our findings on the Japanese fossil records demonstrate that the dispersion of a basal cervid and palaeomerycid between Japan and the Eurasian continent had been completed before 18 Ma. Further studies with additional material would reveal detailed taxonomic relationships and evolutionary process of the Japanese pecorans in the Burdigalian.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"182 - 204"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48062648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. The Ichinotani Formation distributed in the Fukuji area, Hida Marginal Terrane, central Japan, consists of fossiliferous bedded limestone intercalating reddish mudstone and sharpstone conglomerate with a continental margin affinity. The lower part of the formation in the studied area is subdivided into five fusuline zones from lower to upper, Eostaffella kanmerai, Pseudostaffella antiqua, Pseudostaffella kanumai, Profusulinella fukujiensis, and Profusulinella dagmarae. These five zones are probably correlated to the Visean/Serpukhovian (Venevian/Tarusian), middle part of the Bashkirian (Akavasian), middle to upper part of the Bashkirian (Askynbashian to Tashatinian), upper part of the Bashkirian (Tashatinian to Asatausian), and uppermost Bashkirian (Asatausian), respectively, of the stratotypes of the Russian Platform and the South Urals based on the biostratigraphy, faunal composition and correlation of foraminifers. There are remarkable faunal transitions between the Eostaffella kanmerai and Pseudostaffella antiqua zones. Almost coeval Pseudostaffella–Profusulinella assemblages are recognized between the upper part of the Lower Member and the lower part of the Middle Member in the type section of the Ichinotani Formation. Thirty-three species of foraminifers are paleontologically noted and compared to those mainly of the type materials and the taxa to have been described from the Ichinotani Formation.
{"title":"Carboniferous Foraminifers of the Lower Part of the Ichinotani Formation, Hida Marginal Terrane, Japan","authors":"F. Kobayashi, H. Furutani, D. Vachard","doi":"10.2517/PR200033","DOIUrl":"https://doi.org/10.2517/PR200033","url":null,"abstract":"Abstract. The Ichinotani Formation distributed in the Fukuji area, Hida Marginal Terrane, central Japan, consists of fossiliferous bedded limestone intercalating reddish mudstone and sharpstone conglomerate with a continental margin affinity. The lower part of the formation in the studied area is subdivided into five fusuline zones from lower to upper, Eostaffella kanmerai, Pseudostaffella antiqua, Pseudostaffella kanumai, Profusulinella fukujiensis, and Profusulinella dagmarae. These five zones are probably correlated to the Visean/Serpukhovian (Venevian/Tarusian), middle part of the Bashkirian (Akavasian), middle to upper part of the Bashkirian (Askynbashian to Tashatinian), upper part of the Bashkirian (Tashatinian to Asatausian), and uppermost Bashkirian (Asatausian), respectively, of the stratotypes of the Russian Platform and the South Urals based on the biostratigraphy, faunal composition and correlation of foraminifers. There are remarkable faunal transitions between the Eostaffella kanmerai and Pseudostaffella antiqua zones. Almost coeval Pseudostaffella–Profusulinella assemblages are recognized between the upper part of the Lower Member and the lower part of the Middle Member in the type section of the Ichinotani Formation. Thirty-three species of foraminifers are paleontologically noted and compared to those mainly of the type materials and the taxa to have been described from the Ichinotani Formation.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"107 - 130"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42454261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Ishida, H. T. Trinh, B. Thuy, Lea D. Numberger-Thuy, T. Komatsu, H. D. Doan, M. T. Nguyen, Y. Shigeta, T. Fujita
Abstract. The fossil record of brittle stars, one of the five extant classes of echinoderms, is still rather poorly known. In particular for the Triassic Period, occurrences published to date are strongly biased toward Europe, with only two exhaustively described taxa recorded from the East Asian part of the Tethys Ocean. Here, we record new ophiuroids from the Carnian (Upper Triassic) of the Me area in Ninh Binh Province, Vietnam. The fossils comprise articulated disks and arm fragments preserved as external molds, all original calcite dissolved. We introduce a new genus and species, Triadoleucella meensis, for these specimens that represent the oldest known member of the order Ophioleucida. The ophiuroids were found in mudstones deposited in outer shelf environments below storm wave base. The intact articulation, combined with random orientation and intense fragmentation of individuals suggest effective burial by downslope mudflow prior to or soon after death.
{"title":"A New Genus and Species of Brittle Star (Ophiuroidea: Ophioleucida) from the Upper Triassic (Carnian) of Northern Vietnam","authors":"Y. Ishida, H. T. Trinh, B. Thuy, Lea D. Numberger-Thuy, T. Komatsu, H. D. Doan, M. T. Nguyen, Y. Shigeta, T. Fujita","doi":"10.2517/PR210014","DOIUrl":"https://doi.org/10.2517/PR210014","url":null,"abstract":"Abstract. The fossil record of brittle stars, one of the five extant classes of echinoderms, is still rather poorly known. In particular for the Triassic Period, occurrences published to date are strongly biased toward Europe, with only two exhaustively described taxa recorded from the East Asian part of the Tethys Ocean. Here, we record new ophiuroids from the Carnian (Upper Triassic) of the Me area in Ninh Binh Province, Vietnam. The fossils comprise articulated disks and arm fragments preserved as external molds, all original calcite dissolved. We introduce a new genus and species, Triadoleucella meensis, for these specimens that represent the oldest known member of the order Ophioleucida. The ophiuroids were found in mudstones deposited in outer shelf environments below storm wave base. The intact articulation, combined with random orientation and intense fragmentation of individuals suggest effective burial by downslope mudflow prior to or soon after death.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"147 - 159"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48664185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Microporina articulata notoensis Sakakura, 1936, from the Nanao Calcareous Sandstone (Middle Miocene) was restudied and raised to species rank, mainly based on the orifice morphology. Sakakura interpreted small depressions along lateral sides of the cryptocyst as additional opesiules, but it is not clear whether they function as opesiules or not, based on the SEM image. This and other Neogene to Recent Microporina species in Japan are compared, and one more species, Microporina iwayaensis sp. nov. is erected.
{"title":"Restudy of a Miocene Bryozoan Species, Microporina articulata notoensis Sakakura, 1936 with Description of Another New Species from the Nanao Calcareous Sandstone","authors":"S. Arakawa","doi":"10.2517/PR210018","DOIUrl":"https://doi.org/10.2517/PR210018","url":null,"abstract":"Abstract. Microporina articulata notoensis Sakakura, 1936, from the Nanao Calcareous Sandstone (Middle Miocene) was restudied and raised to species rank, mainly based on the orifice morphology. Sakakura interpreted small depressions along lateral sides of the cryptocyst as additional opesiules, but it is not clear whether they function as opesiules or not, based on the SEM image. This and other Neogene to Recent Microporina species in Japan are compared, and one more species, Microporina iwayaensis sp. nov. is erected.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"231 - 240"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49376752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kase, Y. Kurihara, S. Tomida, Mitsuo Tanabe, Takanobu Yamaoka, Yoshinori Ichihashi, Hitoshi Ohzawa, Y. Takaizumi
Abstract. The turbinid gastropod species Turbo (Lunella) ozawai Otuka, 1938 was described based on two opercula from the lower to middle Miocene Korematsu Formation in Southwest Japan. This inadequate proposal of the new species without the shell character information has confused subsequent taxonomic and faunal studies on the early to middle Miocene species of Turbo in Japan. For the first time, we clarify the shell characters of T. (M.) ozawai based on the type series and newly obtained materials from the Korematsu Formation in the Shobara area, Hiroshima Prefecture, and the Yoshino Formation in the Tsuyama area, Okayama Prefecture, Southwest Japan. The clarification of the shell and opercular characters of T. (M.) ozawai has enabled a taxonomic revision of the previously described four nominal species from early to middle Miocene species of Turbo (Marmarostoma) from the Honshu Arc of the Japanese Islands. Consequently, these four species are reclassified into two species, T. (M.) ozawai and T. (M.) tochiyensis Kanno, 1958; T. (M.) parvuloides Nomura, 1940 and T. (M.) minoensis Itoigawa, 1960 are junior synonyms of T. (M.) ozawai and T. (M.) tochiyensis, respectively. Both species are rare examples of mollusks that thrived along the Honshu Arc throughout the Miocene Climatic Optimum (∼16.9 to 14.7 Ma). The species richness of Turbo (Marmarostoma) is similar to that of the modern species in the warm water region of the Japanese Islands.
{"title":"Revision of Four Species of Turbo (Marmarostoma) (Gastropoda: Turbinidae) from the Lower-Middle Miocene of Japan","authors":"T. Kase, Y. Kurihara, S. Tomida, Mitsuo Tanabe, Takanobu Yamaoka, Yoshinori Ichihashi, Hitoshi Ohzawa, Y. Takaizumi","doi":"10.2517/PR210008","DOIUrl":"https://doi.org/10.2517/PR210008","url":null,"abstract":"Abstract. The turbinid gastropod species Turbo (Lunella) ozawai Otuka, 1938 was described based on two opercula from the lower to middle Miocene Korematsu Formation in Southwest Japan. This inadequate proposal of the new species without the shell character information has confused subsequent taxonomic and faunal studies on the early to middle Miocene species of Turbo in Japan. For the first time, we clarify the shell characters of T. (M.) ozawai based on the type series and newly obtained materials from the Korematsu Formation in the Shobara area, Hiroshima Prefecture, and the Yoshino Formation in the Tsuyama area, Okayama Prefecture, Southwest Japan. The clarification of the shell and opercular characters of T. (M.) ozawai has enabled a taxonomic revision of the previously described four nominal species from early to middle Miocene species of Turbo (Marmarostoma) from the Honshu Arc of the Japanese Islands. Consequently, these four species are reclassified into two species, T. (M.) ozawai and T. (M.) tochiyensis Kanno, 1958; T. (M.) parvuloides Nomura, 1940 and T. (M.) minoensis Itoigawa, 1960 are junior synonyms of T. (M.) ozawai and T. (M.) tochiyensis, respectively. Both species are rare examples of mollusks that thrived along the Honshu Arc throughout the Miocene Climatic Optimum (∼16.9 to 14.7 Ma). The species richness of Turbo (Marmarostoma) is similar to that of the modern species in the warm water region of the Japanese Islands.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"131 - 146"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46598771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. A specimen belonging to the genus Polistes (Vespidae: Polistinae) is described from the Chibanian (Middle Pleistocene) Shiobara Group, Tochigi Prefecture, Japan. The morphology of the forewing and first gastral tergum indicated a more accurate assignment of Polistes sp. This specimen is the first fossil of a paper wasp to be identified in Japan.
{"title":"A Fossil Paper Wasp (Vespidae: Polistinae) from the Chibanian (Middle Pleistocene) Shiobara Group in Tochigi Prefecture, Japan","authors":"Yui Takahashi, Hiroaki Aiba","doi":"10.2517/PR210027","DOIUrl":"https://doi.org/10.2517/PR210027","url":null,"abstract":"Abstract. A specimen belonging to the genus Polistes (Vespidae: Polistinae) is described from the Chibanian (Middle Pleistocene) Shiobara Group, Tochigi Prefecture, Japan. The morphology of the forewing and first gastral tergum indicated a more accurate assignment of Polistes sp. This specimen is the first fossil of a paper wasp to be identified in Japan.","PeriodicalId":54645,"journal":{"name":"Paleontological Research","volume":"27 1","pages":"205 - 210"},"PeriodicalIF":0.9,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43762671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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