Kaminaka crossroad on Prefectural Road 588: Middle Miocene, Japan
collected 2003

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Ostreida - Ostreidae
Crassostrea sp. Sacco 1897
Gastropoda - Potamididae
Vicarya sp. d'Archiac and Haime 1854
Osteichthyes - Testudines - Trionychidae
1 specimen
shell fragment
Osteichthyes - Testudines - Geoemydidae
1 specimen
MTE1, partial shell.
see common names

Geography
Country:Japan State/province:Kagoshima County:Kawachi,
Coordinates: 30.4° North, 130.9° East (view map)
Paleocoordinates:
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Miocene
10 m.y. bin: Cenozoic 5
Key time interval: Middle Miocene
Age range of interval: 15.98 - 11.63 m.y. ago
Stratigraphy
Geological group:Kukinaga Formation:Kawachi
Stratigraphy comments: The formation has never been dated, but Inoue (1992) estimated that it was formed in approximately 16 Ma on the basis of the molluscan fossils. Inoue (1992) also examined planktonic foraminiferans from the Hirota Mudstone and Sandstone Member (the second member from the top of the Osaki Formation) and correlated it with N13 to N15 (late middle to early late Miocene) of Blow (1969). Further, Ogasawara (1997) dated quartz–porphyry in the Tashiro Formation (underlying the Kawachi Formation) approximately to 15.6 Ma by using K–Ar dating and Yamaguchi et al. (2012) re–correlated the planktonic foraminiferal assemblage from the Osaki Formation in Inoue (1992) with M6 to PL2 (middle Miocene to early Pliocene) of Wade et al. (2011). In this study, we follow these previous works and consider the age of the Kawachi Formation as the early middle Miocene.
Lithology and environment
Primary lithology: mudstone
Environment:lacustrine - large
Geology comments: Although O. tanegashimensis was discovered from shallow marine sediment (the Kawachi Formation), this species appears to have had a freshwater habitat because O. sinensis occurs in subtropical rivers, ponds, and lakes in lowland areas of Taiwan, southern China, and northern Vietnam (Iverson 1992; Ernst and Barbour 1989). Ocadia nipponica has also been discovered from fluvial deposit, and is considered to be a freshwater species. Co–occurrence of O. tanegashimensis and a shell fragment of a trionychid turtle supports this ecological inference.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection excludes:some macrofossils
Collection methods:selective quarrying,field collection,survey of museum collection
Reason for describing collection:taxonomic analysis
Collection dates:July 2003
Collection method comments: Material deposited in the collection of the Minamitane–cho Board of Education (MTE1).
Metadata
Database number:218913
Authorizer:E. Vlachos Enterer:E. Vlachos
Created:2021-03-04 07:59:35 Last modified:2025-02-22 15:12:02
Access level:the public Released:2021-03-04 07:59:34
Creative Commons license:CC0
Reference information

Primary reference:
75822. A. Takahashi, K. Oki, T. Ishido and R. Hirayama. 2013. A new species of the genus Ocadia (Testudines: Geoemydidae) from the middle Miocene of Tanegashima Island, southwestern Japan and its paleogeographic implications. Zootaxa 3647(4):527-540 [E. Vlachos/E. Vlachos/P. Wagner]