Sample USr-01, upperstream USr section, Sorachi River: Early Pliocene, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Ostracoda - Podocopida - Cytheruridae
6 specimens
16 specimens
Ostracoda - Podocopida - Cytheridae
1 specimen
1 specimen
Ostracoda - Podocopida - Trachyleberididae
1 specimen
Ostracoda - Podocopida - Bythocytheridae
Bythoceratina sp. Hornibrook 1952
1 specimen
Ostracoda - Podocopida - Pectocytheridae
1 specimen
Ostracoda - Podocopida - Hemicytheridae
6 specimens
102 specimens
see common names

Geography
Country:Japan State/province:Hokkaido Region County:Hokkaido Prefecture
Coordinates: 43.6° North, 142.0° East (view map)
Paleocoordinates:43.4° North, 141.0° East (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period: Neogene Epoch: Pliocene
Stage: Zanclean 10 m.y. bin: Cenozoic 6
Key time interval: Early Pliocene
Age range of interval: 5.333 - 3.6 m.y. ago
Stratigraphy
Formation:Takikawa Member:Horokura
Stratigraphy comments: "The USr section corresponds to the lower part of the Horokura Sandstone and Mudstone Member" of the Takikawa Formation (Pliocene). USr-01 from Horokura
Lithology and environment
Primary lithology:gray,blue sandstone
Secondary lithology:fine conglomerate
Includes fossils?Y
Lithology description: Usr-01 is from the fine conglomerate layer. "The USr section consists of alternating layers of well-sorted grayish-blue fine-grained sandstone, grayish-blue mudstone beds (~30 cm thick), and a massive granule stone layer with a matrix of poorly sorted gray fine-grained sandstone as a matrix (~30 cm thick). "
Environment:estuary/bay
Geology comments: "inner area of a bay" in cold water settings
Taphonomy
Modes of preservation:body
Size of fossils:microfossils
Collection methods and comments
Reason for describing collection:paleoecologic analysis
Metadata
Database number:278623
Authorizer:P. Novack-Gottshall Enterer:P. Novack-Gottshall
Modifier:P. Novack-Gottshall
Created:2026-04-19 07:36:46 Last modified:2026-04-19 07:44:21
Access level:the public Released:0000-00-00 00:00:00
Creative Commons license:
Reference information

Primary reference:
94627. K. Mukai and G. Tanaka. 2025. Early Pliocene ostracodes from the Takikawa Formation in Hokkaido, northern Japan, and the new genus Woodeltia moving in the North Pacific Ocean. Journal of Paleontology 99(6):1401-1417 [P. Novack-Gottshall/P. Novack-Gottshall]