Nakagumi (locality 1): Pliocene, Japan
collected by Yoshio Nakagawa 1985
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Chondrichthyes
- Lamniformes
- Lamnidae
|
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| TFM-V-003 | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan |
| Coordinates: | 36.7° North, 138.1° East (view map) |
| Paleocoordinates: | 36.5° North, 137.3° East (Wright 2013) |
| Basis of coordinate: | estimated from map |
| Geographic resolution: | outcrop |
Time
| Period: | Neogene | Epoch: | Pliocene |
| 10 m.y. bin: | Cenozoic 6 | ||
| Key time interval: | Pliocene | ||
| Age range of interval: | 5.333 - 2.58 m.y. ago |
Stratigraphy
| Formation: | Ogikubo | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: Ogikubo Sandstone-Mudstone Member, Saku Formation Age: Middle Pliocene (4-3 Ma). Now the Ogikubo Formation. The Early to Late Pliocene planktic foraminifers Globigerina apertura and Neogloboquadrina dutertrei occur in the uppermost Ogikubo Formation, and indicate the lower part of Zone N21 of Blow (1969) dated as c. 3.0 Ma (Tsuchi & Ibaraki, 1988; Fig. 2). Radiolarians of the Spongurus pylomaticus Zone (5.2-4.5 Ma) occur in the Arakurayama Formation, and Pliocene radiolarians of the Spongurus pylomaticus Zone-lower Cycladophora sakaii Zone (5.2-2.6 Ma) are found from the Ogikubo Formation (Motoyama & Nagamori, 2006). These age determinations were confirmed by fission-track age of zircons from tuff layer OT10 in the lower part of the Ogikubo Formation, 3.6 +/- 0.2 Ma (Nagamori et al., 2003), whilst basaltic lava from the Arakurayama Formation has a K-Ar age of 4.2 +/- 0.6Ma (Nagamori et al., 2003). The age of the Takafu and Ogikubo formations is considered to be c. 4-3 Ma (Fig. 2). | |||||
Lithology and environment
| Primary lithology: | "siliciclastic" |
| Environment: | coastal indet. |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | Yoshio Nakagawa | Collection dates: | 1985 |
| Collection method comments: Repository: Togakushi Village Geological and Fossil Museum (TFM) | |||
Metadata
| Database number: | 277722 | ||
| Authorizer: | M. Clapham | Enterer: | M. Clapham |
| Modifier: | M. Clapham | Research group: | vertebrate |
| Created: | 2026-02-07 18:31:03 | Last modified: | 2026-02-07 18:36:13 |
| Access level: | the public | Released: | 0000-00-00 00:00:00 |
| Creative Commons license: |
Reference information
Primary reference:
| 94154. | M. Goto, T. Tanabe, and H. Yoshikawa. 1993. On the fossil teeth of the lamnoid sharks from the Shigarami Formation (Neogene) in the north part of Nagano Prefecture, central Japan. Earth Science (Chikyu Kagaku) 47:507-518 [M. Clapham/M. Clapham] |