Hikagenosawa Fm. of Southern Oyubari (Y070137) (Cretaceous of Japan)

Where: Hokkaido, Japan (44.0° N, 143.0° E: paleocoordinates 53.5° N, 137.0° E)

• coordinate based on political unit

• local area-level geographic resolution

When: M7 Member (Hikagenosawa Formation), Early/Lower Cenomanian (99.6 - 93.5 Ma)

• syn: Hikagenosawa shale

• member-level stratigraphic resolution

Environment/lithology: offshore; lithified mudstone and tuff

• Appears to be a deep water facies, but near enough to shore to have tuffs. Collection consist of inoceramids and ammonites, regarded as deep-water faunas.
• M7: laminated mudstone with acidic tuff intercalations

Primary reference: F. Kawabe. 2000. Cretaceous Stratigraphy in the Oyubari Area, Central Hokkaido, Japan. Bulletin of the National Science Museum. Series C: Geology and Paleontology 26(1-2):9-56 [A. Miller/C. Ferguson]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 62649: authorized by Arnold Miller, entered by Chad Ferguson on 25.07.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• Biostratigraphic topic of the paper might preclude mention of taxa other than inoceramids and ammonites
Show authors, comments, and common names
unclassified
  -
Miogaudryceras yokoii
Miogaudryceras yokoii
1-2 specimens
Cephalopoda
 Ammonitida - Kossmaticeratidae
Marshallites sp.
Marshallites sp. Matsumoto 1955 ammonite
1-2 specimens
 Ammonitida - Desmoceratidae
Desmoceras (Pseudouhligella) ezoanum
Desmoceras (Pseudouhligella) ezoanum Matsumoto 1941 ammonite
1-2 specimens
 Ammonitida - Tetragonitidae
Zelandites sp.
Zelandites sp. Marshall 1926 ammonite
1-2 specimens
Bivalvia
 Myalinida - Inoceramidae
Inoceramus cf. reduncus, Inoceramus ginterensis, Inoceramus ex gr. pennatulus
Inoceramus cf. reduncus clam
1-2 specimens
Inoceramus ginterensis Pergament 1966 clam
3-8 specimens; two seperate occurrences: one has aff species prefix (rare: 1-2 specimens).
Inoceramus ex gr. pennatulus Pergament 1966 clam
1-2 specimens