Kanagasako, Tsubuta, Sanyoonoda-shi: Julian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
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Ophiuroidea
- Ophiacanthida
- Ophiacanthidae
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Leadagmara gracilispina n. gen., n. sp.
Thuy et al. 2013
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28 specimens | |||||||||
| and hundreds of dissociated ossiles | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan |
| Coordinates: | 34.0° North, 131.1° East (view map) |
| Paleocoordinates: | 16.1° North, 134.0° East (Wright 2013) |
| Basis of coordinate: | stated in text |
| Geographic resolution: | outcrop |
Time
| Period: | Triassic | Epoch: | Late Triassic |
| Stage: | Carnian | 10 m.y. bin: | Triassic 3 |
| Key time interval: | Julian | ||
| Age range of interval: | 237 - 233.6 m.y. ago |
Stratigraphy
| Formation: | Nakatsuka | ||||
| Stratigraphic resolution: | group of beds | ||||
| Stratigraphy comments: Ammonoids including Trachyceras cf. desatoyense (Johnston) (Ishibashi et al. 1990), Protrachyceras cf. archelaus (Laube) and Paratrachyceras cf. aonoides (von Mojsisovics) (Ishibashi et al. 2007), all document an early Carnian age | |||||
Lithology and environment
| Primary lithology: | lithified "shale" |
| Lithology description: The grain size spectrum of the shale layers varies from pure clay to silty clay with numerous detrital mica flakes | |
| Environment: | coastal indet. |
| Geology comments: Interpreted as a shallow, nearshore marine deposit (Tokuyama 1962). It overlies
the limnic to deltaic deposits of the Kajiura Formation. | |
Taphonomy
| Modes of preservation: | mold/impression |
| Size of fossils: | macrofossils |
Collection methods and comments
| Reason for describing collection: | taxonomic analysis |
| Museum repositories: | NHMW |
| Collection method comments: Repository: Mine City Museum of History and Folklore, Yamaguchi Prefecture, Japan (MMHF); The National Museum of Nature and Science, Tokyo, Japan (NMNS); Geowissenschaftliches Museum der Universität Göttingen, Göttingen, Germany (GZG.INV); and Naturhistorisches Museum Wien, Vienna, Austria (NHMW) | |
Metadata
| Database number: | 152134 | ||
| Authorizer: | M. Clapham | Enterer: | M. Clapham | Research group: | marine invertebrate |
| Created: | 2013-11-08 17:09:24 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2013-11-08 17:09:24 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 48827. | B. Thuy, Y. Ishida, E. Doi and A. Kroh. 2013. New ophiacanthid brittle stars (Echinodermata: Ophiuroidea) from the Upper Triassic of Japan: first insights into the origin and evolution of an extant deep-sea group. Journal of Systematic Palaeontology 11:515-530 [M. Clapham/M. Clapham] |