Shobara City: Burdigalian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Osteichthyes
- Cetacea
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| see common names | |||||||
Geography
| Country: | Japan | State/province: | Hiroshima | County: | Shobara |
| Coordinates: | 34.9° North, 133.0° East (view map) | ||||
| Paleocoordinates: | 34.5° North, 130.4° East (Wright 2013) | ||||
| Basis of coordinate: | estimated from map | ||||
| Geographic resolution: | local area |
Time
| Period: | Neogene | Epoch: | Miocene |
| Stage: | Burdigalian | 10 m.y. bin: | Cenozoic 5 |
| Key time interval: | Burdigalian | ||
| Age range of interval: | 20.45 - 15.98 m.y. ago | ||
| Age estimate: | 17 to 14.9 Ma (other) |
Stratigraphy
| Geological group: | Bihoku | Formation: | Korematsu | ||
| Stratigraphic resolution: | formation | ||||
| Stratigraphy comments: The Korematsu Formation in the Shobara area underlies the Itabashi Formation, and together with latter forms the middle/upper portion of the Bihoku Group [114]. Calcareous nannoplankton correlates the Korematsu Formation and the lower part of the Itabashi Formation with the upper part of nannoplankton zone NN4 [114], suggesting a latest Burdigalian or early Langhian age with a minimum of 14.9 Ma [20, 54]. A further study [115] specifically correlated the Korematsu and Itabashi formations exposed along the stretch of the Saijyo River that yielded the whale fossils with the top of nannoplankton zone NN4, and the beginning of the “Mid-Neogene Climatic Optimum” (ca. 16–15 Ma [49, 116]). By contrast, diatom-based biostratigraphic data place the upper part of the Bihoku Group almost entirely in the late Burdigalian (17.0–16.0 Ma) [35, 36, 117, 118]. Together, these estimates amount to an age range of 17.0–14.9 Ma. (Marx & Fordyce, 2015) | |||||
Lithology and environment
| Primary lithology: | not reported |
| Includes fossils? | Y |
| Environment: | marine indet. |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Reason for describing collection: | general faunal/floral analysis |
Metadata
| Database number: | 278637 | ||
| Authorizer: | M. Uhen | Enterer: | M. Uhen | Research group: | vertebrate |
| Created: | 2026-04-23 12:53:18 | Last modified: | 2026-04-23 12:53:18 |
| Access level: | the public | Released: | 0000-00-00 00:00:00 |
| Creative Commons license: |
Reference information
Primary reference:
| 94656. | T. Yamaoka. 1995. A shark tooth embedded in the ulna of a fossil whale from Shobara. Journal of the Hiba Society of Natural History 164:63-64 [M. Uhen/M. Uhen/M. Uhen] |