Hobetsu River, Mobetsu (Locality 4): Early/Lower Maastrichtian, Japan
collected by S. Araki 1980
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Reptilia
- Testudines
- Dermochelyidae
|
||||||||||
|
Mesodermochelys undulatus
Hirayama and Chitoku 1996
|
1 specimen | |||||||||
| HMG 7, sacral and caudal vertebrae, hind limbs, and posterior portion of shell | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan | State/province: | Hokkaido | County: | Hobetsu |
| Coordinates: | 42.8° North, 142.1° East (view map) | ||||
| Paleocoordinates: | 46.9° North, 131.4° East | ||||
| Basis of coordinate: | estimated from map | ||||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Late/Upper Cretaceous |
| Stage: | Maastrichtian | 10 m.y. bin: | Cretaceous 8 |
| Key time interval: | Early/Lower Maastrichtian | ||
| Age range of interval: | 72.10000 - 66.00000 m.y. ago |
Stratigraphy
| Geological group: | Yezo | Formation: | Hakobuchi | Member: | Lower sandy Siltstone |
| Stratigraphic resolution: | bed | ||||
| Stratigraphy comments: The middle portion of the lower sandy siltstone formation consists of dark gray sandy siltstone, bearing marine invertebrates such as Inoceramus (Cataceramus) shikotanensis, Pachydiscus (Neodesmoceras) japonicus and Neophylloceras hetonaiensis which indicate an early lower Maastrichtian age. | |||||
Lithology and environment
| Primary lithology: | concretionary,gray sandy,calcareous siltstone |
| Includes fossils? | Y |
| Lithology description: All material described here was contained in sandy calcareous concretions which came from the surface outcrop of the lower sandy siltstone formation of the Hakobuchi Group as found in Central Hokkaido. It is characterised by coarse grained sediments consisting mainly of sandstones... The middle portion of the lower sandy siltstone formation consists of dark gray sandy siltstone, bearing marine invertebrates such as Inoceramus (Cataceramus) shikotanensis, Pachydiscus (Neodesmoceras) japonicus and Neophylloceras hetonaiensis which indicate an early lower Maastrichtian age. | |
| Environment: | marine indet. |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
Collection methods and comments
| Collection methods: | surface (float),surface (in situ),mechanical,acetic,field collection | ||
| Reason for describing collection: | taxonomic analysis | ||
| Collectors: | S. Araki | Collection dates: | September 4, 1980 |
| Collection method comments: Collection of Hobetsu Museum at Hobetsu-cho, Hokkaido, Japan | |||
Metadata
| Database number: | 129275 | ||
| Authorizer: | R. Benson | Enterer: | R. Benson |
| Modifier: | P. Mannion | Research group: | vertebrate |
| Created: | 2012-06-23 00:40:03 | Last modified: | 2021-03-16 13:26:12 |
| Access level: | the public | Released: | 2012-06-23 00:40:03 |
| Creative Commons license: | CC BY |
Reference information
Primary reference:
| 42111. | R. Hirayama and T. Chitoku. 1996. Family Dermochelyidae (superfamily Chelonioidea) from the Upper Cretaceous of north Japan. Transactions and Proceedings of the Palaeontological Society of Japan. New series 184:597-622 [R. Benson/R. Benson] |