著者

成田 敦史 矢部 淳 松本 みどり 植村 和彦

出版者

一般社団法人 日本地質学会

雑誌

地質学雑誌 (ISSN:00167630)

巻号頁・発行日

vol.123, no.3, pp.131-145, 2017-03-15 (Released:2017-06-15)

参考文献数

35

被引用文献数

2

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北海道北部の下川町上名寄に分布する中部~上部中新統パンケ層から33分類群より構成される大型植物化石群(上名寄植物群)を得た.パンケ層の堆積相解析と植物化石の組成,産状を基に上名寄植物群の示す古植生を復元した.上名寄植物群の示す古植生は,カツラ属やAcer subcarpinifolium(カエデ属),トウヒ属が優占する河畔植生,トクサ属やタケ亜科単子葉類,トウヒ属,ヤナギ属が優占する後背湿地植生,カツラ属やヤナギ属,フジキ属が優占する湖岸植生,湖周辺ではあるがブナ属優占の山地斜面のブナ林が強調された植生の4タイプの植生を認めた.上名寄植物群の組成的特徴は後期中新世~鮮新世前期の三徳型植物群と言える.堆積相と化石の産状から,上名寄植物群の主要構成種は,それらの近似現生種と同じ生育環境と考えられる.したがって,生態的に現在の植生に対比可能な群集が少なくとも北海道においては,中期中新世後期~後期中新世に成立していたことを示している.

著者

成田 敦史 植村 和彦 松本 みどり 矢部 淳

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.92, pp.5-18, 2012-09-28 (Released:2017-10-03)

参考文献数

44

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A late Middle Miocene megafossil flora (Konan Flora) is preserved in lacustrine deposits in the Konan Tuffaceous Sandstone and Mudstone Member of the Bifuka Formation in Shibetsu City, Hokkaido, the northernmost island in Japan. The Konan Flora is composed of 38 taxa in 17 families and 24 genera and includes 4 evergreen conifers, 1 monocotyledonous perennial herb, 33 deciduous dicots, and 2 seeds of unknown affinity. The most dominant species in the flora is Fagus palaeojaponica, followed by Acer subcarpinifolium, A. protojaponicum, Picea sp., Salix sp., Cercidiphyllum crenatum, Betula protoglobispica, and Cladrastis chaneyi. The vegetation inferred from the Konan Flora is broad-leaved deciduous or mixed northern hardwood forest which is typical in northern Japan at the Middle Miocene. The composition and components of the Konan flora are similar to those of the Late Miocene Mitoku-type floras in Hokkaido. The leaf physiognomy and quantitative climate analysis based on the CLAMP (Climate Leaf Analysis Multivariate Program) revealed that the prevailing climate was a wet cool temperate climate similar to modern Hokkaido or northern Honshu. Compared with Sakipenpetsu flora (early Middle Miocene), Shanabuchi flora (Late Miocene) and Rubeshibe flora (Early Pliocene), there were no great differences between the Konan flora and those three floras in terms of climatic conditions.

著者

薄井 重雄 高橋 啓一 阿部 勇治 松本 みどり

出版者

日本古生物学会

雑誌

化石 (ISSN:00229202)

巻号頁・発行日

vol.95, pp.7-17, 2014-03-31 (Released:2017-10-03)

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The coronal sutures of nine specimens representing eight species of Japanese three pointed deer from the Pliocene-Pleistocene were investigated. Patterns of the coronal sutures are clearly observed in six specimens representing five species: Cervus praenipponicus from Kawasaki and Ichihara, C. akiyoshiensis from Mine, C. kazusensis from Otsu, C. shimabarensis from Minamishimabara and an unidentified specimen from Taga. It is advantageous to paleontology that the coronal sutural patterns are observable even in fragmentary fossil specimens. Combined with morphology of antlers, it is useful for classification of three pointed deers. The sutures of C. praenipponicus, C. kazusensis and C. shimabarensis are "W"- shape or open pentagonal shape expanding to the rostrad. In contrast, the suture of the Taga specimen exhibits a "V" -shape curve. Therefore, at least two groups are discriminated in Pliocene-Pleistocene three pointed deer species inhabited Japanese Islands. The "W" -shape suture is well observed in the extant Cervinae C. unicolor, C. nippon and C. elaphus, while the "V" -shaped type is seen in C. timorensis, C. eldi, Axis porcinus, Dama dama and Elaphurus davidianus. The Japanese three pointed deer species having the "W" -shaped sutures are closely related to C. unicolor. On the other hand, the Taga specimen having a "V" -shaped suture is supported the relation to C. timorensis or A. porcinus. It conflicts with the general arguments on Cervinae that A. porcinus is not closely related to C. unicolor or C. timorensis. The Taga specimen needs further reaserch utilizing other skeletons from the same locality to determine its taxonomic position.