Kaizawa Valley. Bed d.: Smithian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Cephalopoda
- Ceratitida
- Aspenitidae
|
||||||||||
|
Cephalopoda
- Ceratitida
- Meekoceratidae
|
||||||||||
|
= Juvenites sinuosus
Kiparisova 1947
|
Shigeta and Nguyen 2014 | |||||||||
|
Cephalopoda
- Ceratitida
- Paranannitidae
|
||||||||||
| (1 measurement) | ||||||||||
|
Owenites shimizui
(Sakagami 1955)
|
||||||||||
| (1 measurement) | ||||||||||
|
Cephalopoda
- Ceratitida
- Dieneroceratidae
|
||||||||||
|
Dieneroceras iwaiense
(Sakagami 1955)
|
||||||||||
| (9 measurements) | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan | State/province: | Tokyo-to | County: | Nishitama-gun |
| Coordinates: | 35.0° North, 139.0° East (view map) | ||||
| Paleocoordinates: | 2.4° North, 135.3° East (Wright 2013) | ||||
| Basis of coordinate: | based on nearby landmark | ||||
| Geographic resolution: | local area |
Time
| Period: | Triassic | Epoch: | Early Triassic |
| Stage: | Olenekian | 10 m.y. bin: | Triassic 1 |
| Key time interval: | Smithian | Ammonoid zone: | Owenites koeneni |
| Age range of interval: | 250.8 - 248.6 m.y. ago |
Stratigraphy
| Formation: | Iwai | ||||
| Local order: | bottom to top | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: The ammonoids are listed as Meekoceras Zone (=Smithian) | |||||
Lithology and environment
| Primary lithology: | lenticular,black "shale" |
| Includes fossils? | Y |
| Lithology description: black shale. Lowe fossil bed occurs about 2m above base of the upper member (unit d) , where the fossils occur in lenses of black limestone. The upper fossil bed is 17m above the lower fossil bed and consists of marl lenses. | |
| Environment: | marine indet. |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | surface (in situ),field collection |
| Reason for describing collection: | taxonomic analysis |
| Museum repositories: | MCZ |
| Collection method comments: Some specimens are held at Tokyo University of Education | |
Metadata
| Database number: | 44043 | ||
| Authorizer: | A. McGowan, M. Clapham | Enterer: | A. McGowan, M. Clapham |
| Modifier: | P. Wagner | Research group: | marine invertebrate |
| Created: | 2004-08-31 09:07:30 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2004-08-31 09:07:30 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 11561. | B. Kummel and S. Sakagami. 1960. Mid-Scythian Ammonites from Iwai Formation, Japan. Breviora 126:1-11 [A. McGowan/A. McGowan/A. McGowan] |
Secondary references:
| 50776 | Y. Shigeta and H. D. Nguyen. 2014. Cephalopods. In Y. Shigeta, T. Komatsu, T. Maekawa, H. T. Dang (eds.), Olenekian (Early Triassic) stratigraphy and fossil assemblages in northeastern Vietnam. National Museum of Nature and Science Monographs 45:65-167 [M. Clapham/M. Clapham] |