Urakawa Dam: Aptian, Japan
collected by M. Futakami, Y. Kawashita 1994

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda - Ammonitida - Acanthohoplitidae
Rhytidoplites adkinsi (Humphrey 1949)
Colombiceras spathi Humphrey 1949
Cephalopoda - Ammonitida - Douvilleiceratidae
Cheloniceras sp. Hyatt 1903
Cephalopoda - Ammonitida - Tetragonitidae
Eogaudryceras sp. Spath 1927
Cephalopoda - Ammonitida - Desmoceratidae
Melchiorites sp. Spath 1923
Cephalopoda - Phylloceratida - Phylloceratidae
Hypophylloceras sp. (Salfeld 1924)
see common names

Geography
Country:Japan
Coordinates: 42.2° North, 142.8° East (view map)
Paleocoordinates:39.3° North, 177.8° East (Wright 2013)
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Cretaceous Epoch: Early Cretaceous
Stage: Aptian 10 m.y. bin: Cretaceous 3
Key time interval: Aptian
Age range of interval: 121.4 - 113.2 m.y. ago
Stratigraphy
Geological group:Yezo Formation:Tsukenai
Stratigraphic resolution:group of beds
Stratigraphy comments: Detailed biostratigraphic position unknown, but correlation indicates a late early to early late Aptian age for these taxa.
Lithology and environment
Primary lithology:gray lithified sandy siltstone
Lithology description: Dark gray sandy siltstone
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collectors:M. Futakami, Y. Kawashita Collection dates:1994
Collection method comments: Repository: National Museum of Nature and Science, Tsukuba, Ibaraki
Metadata
Database number:180422
Authorizer:M. Clapham Enterer:M. Clapham
Modifier:M. Clapham Research group:marine invertebrate
Created:2016-07-16 11:21:17 Last modified:2025-02-22 15:12:02
Access level:the public Released:2016-07-16 11:21:17
Creative Commons license:CC0
Reference information

Primary reference:
65674. M. Futakami. 2018. Aptian ammonite fauna from the Yezo Group of the Urakawa area in Hokkaido, Japan. Cretaceous Research 89:224-234 [M. Clapham/M. Clapham]