著者
高橋 啓一 北川 博道 添田 雄二 小田 寛貴
出版者
日本古生物学会
雑誌
化石 (ISSN:00229202)
巻号頁・発行日
no.84, pp.74-80, 2008-10-01

The Churui specimen was found in 1969 and 1970 from Bansei, Churui, Makubetus-cho, Nakagawa-gun, Hokkaido, and is one of the most important whole skeletons of Palaeoloxodon naumanni. Herein, we reexamine the molar number and specific identification of this specimen. As a result of our observations, four molars that were previously identified as second molars of one individual are re-identified as third molars of one individual. These molars correspond to the group 25-27 of Laws (1966), and are therefore assumed to represent an age of about 50 years. Observations of the epiphyseal fusion of the postcranial bones in the Churui specimen support the result that the animal used its third molars. A molar that was previously identified as a third molar from the same individual as the four "second molars" of P. naummmni, is re-identified as a second or third molar of the woolly mammoth Mammuthus primigenius, as determined by morphological characters. It gave a radiocarbon date of 42,850+510BP. Woolly mammoths inhabited Hokkaido from 45ka to 16ka, while the horizon of P. naumanni from Churui is estimated to be 120ka. This suggests that the molar of the woolly mammoth fell from the upper part of the cliff at the excavation site of the Churui specimen, instead of being recovered from the excavation plane.
著者
岡村 喜明 高橋 啓一 琵琶湖博物館資料調査協力員
出版者
日本古生物学会
雑誌
化石 (ISSN:00229202)
巻号頁・発行日
no.55, pp.9-15, 1993-11-30

Fossil footprints of a bird referable to the suborder Gruidea were found from the Pliocene Kobiwako formation of Mie Prefecture, central Japan. The footprints are relatively large and show four toes. Toes II to IV direct forwards with a wide splay angles, while toe I points backwards at a low position. Each toe is wide and with a claw impression at the tip. Metatarsal impression is preserved on the sole. A small area of webbing is present between III and IV only. The stride is 320〜500mm. This record provides additional information about the fauna of the Pliocene Kobiwako formation.
著者
高橋 啓一 小林 巌雄
出版者
地学団体研究会
雑誌
地球科學 (ISSN:03666611)
巻号頁・発行日
vol.40, no.1, pp.39-46b, 1986-01-25
被引用文献数
2

Three elephant molars from the Pleistocene were found in Niigata Prefecture and reported by MATSUMOTO et al. (1968) have been re-examined. These molars were identified by MATSUMOTO et al. (1968) as Loxodonta (Palaeoloxodori) yabei, L. (P.*) tokunagai junior (=Palaeoloxodon naumanni), but morphological and stratigraphical studies have identified these molars as being from an archtipal mammoth. Specifically, this morphological study identified the Monzen specimen as Mammuthus protomammonteus. In comparison with the measurement of molars of the genus Mammuthus in Europe by MAGLIO (1973), the Monzen specimen is similar to M. armeniacus. This shows that the progression of stages in the development of genus Mammuthus is similar to Europian counterpart. Meanwhile a geological survey has revealed that the Mitama specimen occured in a SK030 bed (1.30 m. y. B. P.), which is the key bed of the most upper part of the middle Formation in the Uonuma Group. Therefore the importance of this specimen to discussion is that the meridionalis type shifted into the armeniacus type in Japan.
著者
高橋 啓一 野苅家 宏
出版者
日本地質学会
雑誌
地質學雜誌 (ISSN:00167630)
巻号頁・発行日
vol.86, no.7, pp.455-459_1, 1980-07-15
被引用文献数
2