著者

伊藤 剛 中村 佳博

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.110, pp.3-16, 2021-09-30 (Released:2021-10-15)

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Jurassic accretionary complex of the Chichibu belt is distributed in the western Akaishi Mountains, central Japan. The Miocene Wada Formation, composed mainly of mudstone with basal conglomerate, is exposed in Minami-Shinano, Iida City, Nagano Prefecture, central Japan. This article reports the occurrences of Permian, Triassic, and Jurassic radiolarians from the Jurassic accretionary complex and Triassic radiolarians from the chert pebbles within the basal conglomerate of the Wada Formation. The chert pebbles are most probably derived from accretionary complex of the Chichibu belt exposed near the distributional area of the Wada Formation. Meanwhile, clasts of Cretaceous-Paleogene chert derived from the Shimanto belt nor metamorphic rock from the Sambagawa belt have never been discovered from the Wada Formation so far. This implies that the Shimanto and Sambagawa belts have not largely exposed in the Miocene in the hinterland of the Wada Formation.

著者

小林貞一 鹿間時夫編

出版者

日本古生物学会

巻号頁・発行日

1970

著者

吉田 純輝 カーペンター ケネス

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.108, pp.11-21, 2020-09-30 (Released:2020-10-16)

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Vertebrate burrows from the Mesozoic of North America have been scarcely known. We report two different burrows (burrows A and B) produced by small animals in the Lower Cretaceous (Albian–Cenomanian) Mussentuchit Member of the Cedar Mountain Formation, Utah, USA. The burrow-bearing bed of the Mussentuchit Member consists of poorly-drained paleosols, and the burrows are infilled with light-colored carbonate probably due to a rise in a regional water table. Both burrows were found in-situ and inclined downwards. The burrow A is 60 cm long, and terminated in an expanded distal chamber, whereas the burrow B is 100 cm long and branched, with some small expanded chambers in the middle of the tunnel. Both tunnels have the width to height ratio larger than 1.3. In the burrows, the external walls lack scratch marks, but do show localized, prominent bulges in the burrow A and divots at local expansions of the tunnel in the burrow B. These are unlike those reported from Triassic and Jurassic vertebrate burrows. The estimated weight of the excavators is 3.1 g for the burrow A and 6.8–17.8 g for the burrow B based on the area of each tunnel, indicating that both tracemakers were small animals. A bulge in the burrow B was possibly left by tip of the excavator’s head, as seen in the burrows of modern fossorial squamates. The discovery of a potential squamate burrow from the Cedar Mountain Formation of Utah is consistent with the oldest body fossils of skinks and snakes from the Early Cretaceous.

著者

和仁 良二

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.101, pp.43-59, 2017

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This paper reviews the Cretaceous ammonoid paleontology mainly in the North Pacific region, especially for recent publications. The species diversity changes through Cretaceous and its relevant articles are first reviewed. The review is continued from the points of view of the morphological analyses of shell shape, the relationship between ammonoid fauna and lithofacies, the isotopic analyses of ammonoid shells, the relationship with other organisms, and taphonomy, etc., for normally coiled and heteromorphic ammonoids, respectively. Finally, the characteristic of ammonoid diversity change in North Pacific region and the ammonoid extinction around the Cretaceous/Paleogene boundary are reviewed.

著者

矢島 道子

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.64, pp.36-42, 1998-07-20 (Released:2017-10-03)

参考文献数

17

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ナウマンの講義ノートから, 日本における古生物学の最初の講義は, ほぼチッテルの古生物学を紹介したといえよう.小藤も原田豊吉もミュンヘンで直接チッテルに教えをこうている.日本の古生物学の搖籃期は, よく言われているようにチッテルおよびドイツ学派によって育てられてきた.evolutionについては強烈な反対説ではないが, ドイツ学派の目を通したevolutionの概念の導入が, 日本に定着したと言えよう.私自身はまだチッテルの教科書をきちんと読んでいないが, 日本の多くの簡単な古生物学入門書には, チッテルの古生物学教科書や地質学史・古生物学史の内容が, 今でも, 引用を明記しないで書かれていることがあることもわかってきた.

著者

唐沢 與希 松井 久美子

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.108, pp.3-10, 2020-09-30 (Released:2020-10-16)

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The holotype of Taniwhasaurus mikasaensis (Squamata: Mosasauria) (MCM-M0009) is a partial skull and is registered as a Japan’s National Monument (JNM). Even though this specimen is one of the most famous vertebrate fossils in Japan, its JNM status renders it is very difficult to be handled by researchers, let alone museum visitors. At the same time, “heritage tourism” has attracted attention in museum activities in recent years. Consequently, we have worked on utilization of multimedia data of MCM-M0009 as a new way to introduce this iconic specimen to the public in a much more interactive setting. Of particular importance to be considered is the production cost of such multimedia data, for one, local museums typically operate on a tight budget. As such, this project was carried out with low-cost, readily available tools. The digital 3D model of MCM-M0009 was first generated using a movie application for a smart phone. With the resultant digital 3D model, a total of two downsized plastic models were then produced by a 3D printer for hands-on. Finally, an AR system was built. Anyone with a smart phone and/or an electronic tablet was able to use this system by connecting to the html site provided. We assessed an educational effect of the new multimedia components of Taniwhasaurus mikasaensis in a workshop in July 2019. Questionnaire results gathered from 11 examinees of hands-on models and AR viewing of T. mikasaensis indicated that the new multimedia applications garnered users’ interest only in paleontological aspects of the specimen, but also in most advanced imaging technology. Our result hence revealed that incorporation of multimedia technologies in museum activities had unexpected an interdisciplinary effects. Digital 3D data are deemed effective in preventing total losses of important specimens by disasters, for example, the locality of Utatsusaurus hataii damaged by 2011 Tohoku earthquake and tsunami.

著者

三枝 春生

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.104, pp.35-49, 2018-09-30 (Released:2019-04-03)

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Paleontological expeditions of the Late Cenozoic sediments as well as the reappraisal of the collections of proboscidean fossils kept at various institutes in Myanmar shed new lights on the diversity of the Late Cenozoic proboscidean of Myanmar. The proboscidean fossils of Myanmar can be roughly divided into the Middle Miocene assemblage and those younger than the Middle Miocene. The former includes the elements common to the Chinji Formation of Siwaliks, such as Prodeinotherium cf. pentapotaminae, Zygolophodon cf. metachinjiensis, Protanancus cf. chinjiensis, as well as three un-named species of endemic gomphotheres. Unfortunately, the latter three can't be described formally because they are currently housed in a temple as a part of private collections. The assemblage younger than the Middle Miocene is composed of anancine, sinomastodont, and stegodontids. Myanmar Anancus is similar to A. perimensis from India in the primitive dental structure, suggesting close connection between Indo-Pakistan area and Indochina. The Late Miocene age of Myanmar Sinomastodon fossils supports Asian origin of this genus. However, the early separation of Myanmar Sinomastodon from the Chinese one is suggested by the more derived dental features of the former than the penecontemporaneous Chinese Sinomastodon species. A huge number of stegodontid fossils from the Irrawaddy sediments represent one of the best records of the radiation of this taxon. Numerous molar fossils of Irrawaddy sediments exhibiting the spectrum of dental evolution of stegodontids, from primitive Stegolophodon to highly derived Stegodon. A Stegodon skull from the Upper Irrawaddy exhibits a quite dissimilar morphology to previously known Stegodon crania from the other region of Asia. However, their scientific value is hampered by their poor stratigraphic data. Continuous effort to collect stratigraphically controlled specimens, as well as developments of some new means (e.g. histology) to distinguish fragmentary dental materials at specific level are necessary for the improvement of the situation.

著者

横山 芳春 安藤 寿男 橋本 聡子

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

no.76, pp.32-45, 2004-09-22

被引用文献数

1

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Large oyster shell beds are contained in incised-valley fill deposits of the Cycle 1 of the Miwa Formation, Shimosa Group, Lake Kasumigaura area, Ibaraki Prefecture . This paper describes taphonomic processes of large oyster shell beds well exposed in three localities . Six shell bed types can be recognized on the basis of their lithology, sedimentary facies, mode of fossil occurrence and associated fossils : 1) autochthonous aggregated, 2) autochthonous scattered, 3) parautochthonous aggregated, 4) cross-bedded aggregated, 5) crossbedded scattered and 6) shell-fragment aggregated types. The large oyster shell bed higher than 5 m and wider than 30 m at east Hama (Loc. 1) is characterized by type 1 with two layers of type 3 five to 20 cm thick that seem to have formed by sudden storm events. The second shell bed at west Hama (Loc. 2) shows two mounds 3 m high and or wider than 7-10 m composed of type 1 and covered by massive muddy sediments. This means that the oyster banks were buried under estuary mud. The last example at Sakihama (Loc.3) is the largest oyster shell bed in this area with height of 5m and width of 70m. It can be divided into three unit bounded by two erosional surfaces. The unit I is composed mainly of type 1 representing in situ oyster reefs, and subordinately of 3 formed by reworking through tidal current. The unit II composed of types 4 and 5 forms a shallow channelfilled structure that seems to have been formed as a tidal channel. The overlying unit III above a flat erosional surface mostly consists of type 6. Reworked oyster shell fragments might have concentrated intermittently and condensed through muddy sediment bypassing within tidal flat to embayment.

著者

三倉 健吾 佐藤 慎一

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.110, pp.17-25, 2021-09-30 (Released:2021-10-15)

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In order to extract information about predators from the drillhole characteristics, predatory behavior, drillhole-site selectivity, and preference of prey size and species were examined in Rapana venosa and Glossaulax didyma. Laboratory experiments used predators and the prey bivalves collected from Lake Hamanako in Shizuoka Prefecture, central Japan. Glossaulax didyma always drilled around umbo of bivalve shell, and it preferred similar prey size to its shell size. In contrast, observation of predatory behavior of R. venosa revealed that this species usually killed prey bivalve without drillhole but left slit-shaped scratches or nomarks using probably poisoning or suffocation. Rapana venosa preferred the largest individuals among the different sizes of Ruditapes philippinarum, and it consumed first Cyclina sinensis rather than R. philippinarum and Scapharca kagoshimensis. Our results made clear the differences of the drillhole characteristics and preference of prey size between R. venosa and G. didyma, and enabled to suggest the predator species from the dead and fossil shell.

著者

柴田 正輝 尤 海魯 東 洋一

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.101, pp.23-41, 2017-03-31 (Released:2019-04-03)

被引用文献数

1

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Researches on Japanese dinosaurs make progress dramatically in these decades, since the first dinosaur discovery in the present territory of Japan was made in 1978. Currently, Japanese dinosaur fossils have been unearthed in 16 prefectures of Japan, from Hokkaido to Kagoshima. However, all named Japanese dinosaurs, seven original genus and species, are known only from three localities of the Lower Cretaceous of the Inner Zone of Southwest Japan; Kuwajima and Kitadani formations of the Tetori Group in Ishikawa and Fukui respectively, and “lower formation” of the Sasayama Group in Hyogo. Abundant dinosaur body fossil records from these sites make it possible to compare and discuss as a dinosaur assemblage, namely “Dinosaur Fauna (hereafter DF)”, to other Early Cretaceous DFs in East and Southeast Asia. Comparisons of Shiramine (Kuwajima Fm.), Katsuyama (Kitadani Fm.) and Tamba-Sasayama (“lower formation”) DFs to Hekou, Jehol and Mazongshan DFs from China (North China Craton) and Khorat DF from Thailand (Indosina Terrane) shows interesting results on relationships among faunal changes, paleogeography and paleoenvironment; Shiramine and Jehol DFs, in the early Early Cretaceous, shares faunal similarities under a relatively cool climate, Katsuyama DF, in the middle Early Cretaceous, became to include “southern”-type dinosaurs, such as an allosauroid and a hadrosauroid under somewhat dry and temperate climate, and Tamba-Sasayama DF, in the late Early Cretaceous, includes a neoceratposian shared with Mazongshan DF and sauropod with “peg” like teeth shared with Khorat DF under seasonal dry and temperate climate. Although more sophisticated chronological, paleogeographical, and paleoenvironmental data are needed to understand their relationships, our result implies that there were possibly several routes for dinosaur divergences in the eastern margin of Asia continent, and some taxa might have been originated in the Early Cretaceous of Asia.

著者

速水 格

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.74, pp.81-84, 2003-09-20 (Released:2017-10-03)

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古生物学がもつ不思議な魅力にとりつかれてから間もなく50年になる.半ば偶然であったが, 私はほぼ10年ごとに職場を変わった.学生・院生と学術振興会の研究生を合わせた10年半は別としても, 九州大学理学部に10年, 東京大学総合研究資料館に11年, 同理学部に10年ほど勤務した.そして現在は神奈川大学理学部で停年間際の10年目を迎えている.この間に環境や役割の変化といくつかの奇遇があり, 無節操に研究対象や興味も変わったが, 恩師を始め多くの先輩・同僚, そして学生から有益な刺激を受け, 自由に研究と教育を続けることができたのは誠に幸いであったと感謝している.私が進級論文のフィールドで保存の良い二枚貝の化石層に出会い, 小林貞一先生のすすめで研究の道に入ったのは1950年代の半ばである.戦後の混乱が漸く終息して, 人々の暮らしはほぼ戦前の水準を回復していたが, 大学の研究環境はまだきわめて貧しかった.化石の研究者が使う機器といえば, 薄片を作る回転研磨盤と歯科医が虫歯を削るためのデンタルマシンぐらいのもので, 近代的な研究機器は何もなかった.当時の古生物学を振り返ってみると, 研究者数, 研究対象, 研究のレベルや技術, 研究機器, 情報収集, 思考方法から研究者のもつ価値観や大学の雰囲気まで近年とは比べるべくもない.これは古生物学に限らないであろうが, 誠に今昔の感がある.しかし, 著しい変革と発展の陰に古生物学を巡る科学研究の良き伝統といえるものがいくつか失われたような気もする.また, 昨今の大学改革や性急な業績評価の方法は, 長年をかけて辛抱強く取り組む自然史研究の基盤を危うくしている.このたび, 化石編集部の方から「言いたい放題でよいから学史などを自由に書いてほしい」との依頼を受けてはたと困った.50年ほどの遍歴はあるが, 昭和前半のことはほとんど何も知らないし, その後の経過についても知識は限られている.おそらく駄文になること覚悟で, この半世紀に古生物学を巡って何がどう変わったのか私見を記すことにした.

著者

松本 幸英

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.93, pp.25-35, 2013-03-31 (Released:2017-10-03)

参考文献数

39

著者

近藤 洋一

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.79, pp.81-87, 2006-03-28 (Released:2017-10-03)

参考文献数

39

著者

昆 健志 井上 潤

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.106, pp.5-17, 2019-09-30 (Released:2019-10-25)

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Understanding the process by which life diversifies is one of the central issues in biology. To clarify this process in focal taxa as well as to conduct phylogenetic analyses, a divergence time estimation —an important analysis to determine the timescale of a phylogenetic tree— must be performed. It is thought that the diversification process can be vividly reconstructed by estimating the diversification rate and ancestral geographic area, characterizing ancestral ecology, and mapping ancestral habitats according to a time-calibrated phylogenetic framework. Here we introduce a divergence time estimation method and various other methods for reconstructing the process of diversification based on the time-calibrated phylogenetic framework with some study examples of aquatic organisms, mainly fish.

著者

速水 格

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.49, pp.23-31, 1990

被引用文献数

3

著者

佐藤 たまき

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.85, pp.69-71, 2009

参考文献数

16

著者

鈴木 紀毅

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.99, pp.15-31, 2016-03-31 (Released:2019-04-03)

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A radiolarian taxonomic database with synonymy relationship was created by PaleoTax for Windows that was developed by Hannes Löser. All the taxonomic names published by March, 2015, have been completely entered, reaching 2,780 genera and 15,040 species. In consideration of taxonomic unavailable names and junior synonyms, a total of 13,590 species are regarded as available names. These available names, however, also include the species impossible to be applied for actual specimens due to lack of illustrations and less-characteristic name-bearing type specimens. Excluded such problematic species, a total of 9,870 species are considered to be practically existing. A total of 2,780 genera were established so far, and 1,450 of 2,780 genera are practically usable. Although this database is unable to be in public due to authorships to the illustrations of the name- bearing specimens, it is useful to subjectively search variable information such as the most cited species names (e.g. Cyrtocapsella tetrapera), very rarely cited names (one or twice) (58%), the number of samples (not localities) in the selected geologic time intervals (e.g. 113 samples in Cambrian and Ordovician), the species diversity changes through the geologic time, and other scientific supports. Users to database, however, must aware of the interpretation and quality of the search results.

著者

国府田 良樹 小池 渉 安藤 寿男 上野 輝彌 碓井 和幸

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.81, pp.1-2, 2007-03-30 (Released:2017-10-03)

参考文献数

2

被引用文献数

1

著者

楠橋 直 岡本 隆

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.97, pp.23-37, 2015-03-30 (Released:2017-10-02)

著者

松岡 篤

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.54, pp.1-9, 1993-06-30 (Released:2017-10-03)

被引用文献数

1

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Living radiolarians were collected from the surface water around the Sesoko Island by using a plankton net. The fauna is composed of more than 30 species. The dominant species are Didymocyrtis tetrathalamus tetrathalamus, Euchitonia elegans, Tetrapyle octacantha, Pterocanium praetextum praetextum, Pterocorys zancleus. This paper documents the result of light microscopic observation of the following nine species; Dictyocoryne profunda, Dictyocoryne truncatum, Euchitonia elegans, Lophophaena hispida, Eucyrtidium hexastichum, Pterocanium praetextum praetextum, Carpocanistrum coronatum, Acanthodesmia vinculata, Zygocircus productus.