大山下層

大下山層
読み方	おおやましもそう
英称	Ohyamashimo Formation
地質時代	前期白亜紀アルビアン期
絶対年代	112.1〜106.4Ma
分布	兵庫県丹波篠山市
岩相	礫岩、砂岩、泥岩
命名者	林慶一、藤田早紀、小荒井千人、松川正樹
提唱年	2017年
層群	篠山層群
同時異相	沢田層
外部リンク	https://www.jstage.jst.go.jp/article/geosoc/123/9/123_2017.0016/_article/-char/ja/
	テンプレートを表示

大下山層（おおやましもそう）は、兵庫県丹波篠山市、篠山層群に含まれる前期白亜紀アルビアン期の地層。堆積環境（英語版）は温帯夏雨気候からステップ気候の河川作用である。

動物相

節足動物

Mongolocypris sp.
Conchostraca

軟体動物

Viviparus keishoensis
Sphaerium coreanicum

両生類

^[2]

Hyogobatrachus wadai
Tambabatrachus kawazu

哺乳類

Sasayamamylos kawaii^[3]

トカゲ

Morohasaurus kamitakiensis^[4]
Pachygenys adachii^[5]

恐竜

Tambatitanis amicitiae^[6]

卵化石

Himeoolithus murakamii
Subtiliolithus hyogoensis
Prismatoolithus sp.
Nipponoolithus ramosus
Elongatoolithus sp.
Spheroolithus sp.

脚注

[脚注の使い方]

^ ^a ^b Hayashi, Keiichi; Fujita, Saki; Koarai, Kazuto; Matsukawa, Masaki (2017-09-15). “Stratigraphy and paleoenvironment of the Cretaceous Sasayama Group in the Sasayama area, Hyogo Prefecture, western Japan” (英語). The Journal of the Geological Society of Japan 123 (9): 747–764. doi:10.5575/geosoc.2017.0016. ISSN 0016-7630.
^ Ikeda, Tadahiro; Ota, Hidetoshi; Matsui, Masafumi (June 2016). “New fossil anurans from the Lower Cretaceous Sasayama Group of Hyogo Prefecture, Western Honshu, Japan”. Cretaceous Research 61: 108–123. doi:10.1016/j.cretres.2015.12.024.
^ Kusuhashi, Nao; Tsutsumi, Yukiyasu; Saegusa, Haruo; Horie, Kenji; Ikeda, Tadahiro; Yokoyama, Kazumi; Shiraishi, Kazuyuki (22 May 2013). “A new Early Cretaceous eutherian mammal from the Sasayama Group, Hyogo, Japan”. Proceedings of the Royal Society B: Biological Sciences 280 (1759): 20130142. doi:10.1098/rspb.2013.0142. PMC 3619506.
^ Ikeda, Tadahiro; Ota, Hidetoshi; Tanaka, Tomonori; Ikuno, Kenji; Kubota, Katsuhiro; Tanaka, Kohei; Saegusa, Haruo (February 2022). “A fossil Monstersauria (Squamata: Anguimorpha) from the Lower Cretaceous Ohyamashimo Formation of the Sasayama Group in Tamba City, Hyogo Prefecture, Japan”. Cretaceous Research 130: 105063. doi:10.1016/j.cretres.2021.105063.
^ Ikeda, Tadahiro; Ota, Hidetoshi; Saegusa, Haruo (2 January 2015). “A new fossil lizard from the Lower Cretaceous Sasayama Group of Hyogo Prefecture, western Honshu, Japan”. Journal of Vertebrate Paleontology 35 (1): e885032. doi:10.1080/02724634.2014.885032.
^ Saegusa, Haruo; Ikeda, Tadahiro (12 August 2014). “A new titanosauriform sauropod (Dinosauria: Saurischia) from the Lower Cretaceous of Hyogo, Japan”. Zootaxa 3848 (1). doi:10.11646/zootaxa.3848.1.1.
^ Kubota, Katsuhiro; Kobayashi, Yoshitsugu; Ikeda, Tadahiro (25 July 2024). “Early Cretaceous troodontine troodontid (Dinosauria: Theropoda) from the Ohyamashimo Formation of Japan reveals the early evolution of Troodontinae”. Scientific Reports 14 (1). doi:10.1038/s41598-024-66815-2. PMC 11272788.
^ Tanaka, Tomonori; Chiba, Kentaro; Ikeda, Tadahiro; Ryan, Michael J. (September 2024). “A new neoceratopsian (Ornithischia, Ceratopsia) from the Lower Cretaceous Ohyamashimo Formation (Albian), southwestern Japan”. Papers in Palaeontology 10 (5). doi:10.1002/spp2.1587.

この項目は、日本の地理に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（Portal:日本の地理）。

[SasayamaStrat-1] Hayashi, Keiichi; Fujita, Saki; Koarai, Kazuto; Matsukawa, Masaki (2017-09-15). “Stratigraphy and paleoenvironment of the Cretaceous Sasayama Group in the Sasayama area, Hyogo Prefecture, western Japan” (英語). The Journal of the Geological Society of Japan 123 (9): 747–764. doi:10.5575/geosoc.2017.0016. ISSN 0016-7630.

[TambaFrog-2] Ikeda, Tadahiro; Ota, Hidetoshi; Matsui, Masafumi (June 2016). “New fossil anurans from the Lower Cretaceous Sasayama Group of Hyogo Prefecture, Western Honshu, Japan”. Cretaceous Research 61: 108–123. doi:10.1016/j.cretres.2015.12.024.

[Sasayamamylos-3] Kusuhashi, Nao; Tsutsumi, Yukiyasu; Saegusa, Haruo; Horie, Kenji; Ikeda, Tadahiro; Yokoyama, Kazumi; Shiraishi, Kazuyuki (22 May 2013). “A new Early Cretaceous eutherian mammal from the Sasayama Group, Hyogo, Japan”. Proceedings of the Royal Society B: Biological Sciences 280 (1759): 20130142. doi:10.1098/rspb.2013.0142. PMC 3619506.

[Morohasaurus-4] Ikeda, Tadahiro; Ota, Hidetoshi; Tanaka, Tomonori; Ikuno, Kenji; Kubota, Katsuhiro; Tanaka, Kohei; Saegusa, Haruo (February 2022). “A fossil Monstersauria (Squamata: Anguimorpha) from the Lower Cretaceous Ohyamashimo Formation of the Sasayama Group in Tamba City, Hyogo Prefecture, Japan”. Cretaceous Research 130: 105063. doi:10.1016/j.cretres.2021.105063.

[Pachygenys_adachii-5] Ikeda, Tadahiro; Ota, Hidetoshi; Saegusa, Haruo (2 January 2015). “A new fossil lizard from the Lower Cretaceous Sasayama Group of Hyogo Prefecture, western Honshu, Japan”. Journal of Vertebrate Paleontology 35 (1): e885032. doi:10.1080/02724634.2014.885032.

[Tambatitanis-6] Saegusa, Haruo; Ikeda, Tadahiro (12 August 2014). “A new titanosauriform sauropod (Dinosauria: Saurischia) from the Lower Cretaceous of Hyogo, Japan”. Zootaxa 3848 (1). doi:10.11646/zootaxa.3848.1.1.

[Hypnovenator-7] Kubota, Katsuhiro; Kobayashi, Yoshitsugu; Ikeda, Tadahiro (25 July 2024). “Early Cretaceous troodontine troodontid (Dinosauria: Theropoda) from the Ohyamashimo Formation of Japan reveals the early evolution of Troodontinae”. Scientific Reports 14 (1). doi:10.1038/s41598-024-66815-2. PMC 11272788.

[8] Tanaka, Tomonori; Chiba, Kentaro; Ikeda, Tadahiro; Ryan, Michael J. (September 2024). “A new neoceratopsian (Ornithischia, Ceratopsia) from the Lower Cretaceous Ohyamashimo Formation (Albian), southwestern Japan”. Papers in Palaeontology 10 (5). doi:10.1002/spp2.1587.

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