Fourth formation (W4, KD-34): Neocomian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Osteichthyes
- Ellimmichthyiformes
- Armigatidae
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| KMNH VP 100,211-216, 234 | ||||||||||
| holotype: KMNH VP 100,217; 218-221 | ||||||||||
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Osteichthyes
- Osteoglossiformes
- Wakinoichthiidae
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| Specimen numbers the same as in collection 145246 | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan | State/province: | Fukuoka |
| Coordinates: | 33.8° North, 130.9° East (view map) | ||
| Paleocoordinates: | 46.7° North, 136.5° East (Wright 2013) | ||
| Basis of coordinate: | stated in text | ||
| Geographic resolution: | outcrop |
Time
| Period: | Cretaceous | Epoch: | Early Cretaceous |
| 10 m.y. bin: | Cretaceous 1-2 | ||
| Key time interval: | Neocomian | ||
| Age range of interval: | 143.1 - 125.77 m.y. ago |
Stratigraphy
| Geological group: | Wakino | Formation: | Third | ||
| Stratigraphy comments: The fourth formation (the uppermost formation, W4) correlates to the Upper Wakamiya Formation. The thickness is around 250m. The basal part consists of a conglomerate of white chert and unconformably or conformably overlies the third formation. | |||||
Lithology and environment
| Primary lithology: | lithified sandstone |
| Secondary lithology: | lithified "shale" |
| Includes fossils? | Y |
| Includes fossils? | Y |
| Lithology description: The fourth formation is composed chiefly of sandstone and siliceous shale, with shale, tuff, conglomerate and reddish purple sandstone. | |
| Environment: | terrestrial indet. |
Taphonomy
| Modes of preservation: | adpression |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection excludes: | some genera |
| Collection methods: | chemical,peel or thin section |
| Reason for describing collection: | taxonomic analysis |
| Collection method comments: All fossil specimens used in the present study are deposited in the Kitakyushu Museum and Institute of Natural History (NMNH)
Some specimens were immersed in a bath of 20% HCl and 80% water in 24-48 hours to etch their bones. Latex peels were made from the etched fossils for observation. The outline of large specimens were drawn by tracing the enlarged positive films and detailed drawings were made with a binocular microscope. | |
Metadata
| Database number: | 145246 | ||
| Authorizer: | M. Bell | Enterer: | M. Bell |
| Modifier: | M. Bell | ||
| Created: | 2013-05-30 21:31:52 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2013-05-30 21:31:52 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 46901. | Y. Yabumoto. 1994. Early Cretaceous freshwater fish fauna in Kyushu, Japan. Bulletin of the Kitakyushu Museum of Natural History 13:107-254 [M. Bell/M. Bell] |