Southern coast of Ikantai: Middle Campanian, Japan
collected by H. Kubota

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda - Ammonitida - Nostoceratidae
Amapondella amapondense (van Hoepen 1921)
Bivalvia - Myalinida - Inoceramidae
see common names

Geography
Country:Japan
Coordinates: 42.2° North, 142.7° East (view map)
Paleocoordinates:50.5° North, 132.6° East (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:small collection
Time
Period: Cretaceous Epoch: Late Cretaceous
Stage: Campanian 10 m.y. bin: Cretaceous 7
Key time interval: Middle Campanian
Age range of interval: 83.6 - 72.2 m.y. ago
Stratigraphy
Formation:Chinomigawa
Stratigraphic resolution:bed
Stratigraphy comments: The Chinomigawa Formation in the Urakawa area was divided into four informal members (U2-U5, Sakai and Kanie, 1986). Member U2 contains Sphenoceramus orientalis (Sokolov, 1914) in the upper part and Member U3 includes S. schmidti (Michael, 1899). Both fossils are index inoceramids of early middle Campanian time in the Northwest Pacific region, an age assignment confirmed by both magnetostratigraphy and zircon geochronology (e.g. Kodama, 1990; Shigeta and Tsutsumi, 2018). Collected from area where members U2 and U3 outcrop, in concretions containing Sphenoceramus orientalis.
Lithology and environment
Primary lithology:concretionary lithified mudstone
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:surface (float)
Reason for describing collection:taxonomic analysis
Collectors:H. Kubota
Collection method comments: Repository: Hobetsu Museum, Mukawa (HMG)
Metadata
Database number:226937
Authorizer:M. Clapham Enterer:M. Clapham
Modifier:M. Clapham Research group:marine invertebrate
Created:2022-08-11 18:13:58 Last modified:2025-02-22 15:12:02
Access level:the public Released:2022-08-11 18:13:58
Creative Commons license:CC0
Reference information

Primary reference:
82378. Y. Shigeta and M. Izukura. 2022. Discovery of the heteromorph ammonoid Amapondella amapondense in the middle Campanian of Hokkaido, Japan. Paleontological Journal 26:369-377 [M. Clapham/M. Clapham]