KT035, Kotanbetsu River: Santonian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Cephalopoda - Ammonitida - Nostoceratidae
see common names

Geography
Country:Japan
Coordinates: 44.2° North, 142.0° East (view map)
Paleocoordinates:52.3° North, 136.2° East (Wright 2013)
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period: Cretaceous Epoch: Late Cretaceous
Stage: Santonian 10 m.y. bin: Cretaceous 6
Key time interval: Santonian Inoceramid zone:  Inoceramus amakusensis
Age range of interval: 85.7 - 83.6 m.y. ago
Stratigraphy
Formation:Haborogawa
Local section:Kotanbetsu River Local bed:196.5
Stratigraphic resolution:group of beds
Stratigraphy comments: Among these, the key bed, UHs1 (corresponding to outcrops KT035 and KT037) yields various molluscan fossils, including ammonoids, the subfamily Texanitinae, Heteroptychoceras obatai, and Hyphantoceras orientale, the coleoid Longibelus matsumotoi, and the inoceramid bivalve Inoceramus amakusensis, suggesting the Santonian.
Lithology and environment
Primary lithology: lithified sandstone
Environment:marine indet.
Taphonomy
Modes of preservation:mold/impression
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collection method comments: Repository: Mikasa City Museum (MCM)
Metadata
Database number:240090
Authorizer:M. Clapham Enterer:M. Clapham
Modifier:G. Palazzo Research group:marine invertebrate
Created:2025-04-19 14:01:29 Last modified:2026-09-04 11:16:56
Access level:the public Released:2025-04-19 14:01:29
Creative Commons license:CC0
Reference information

Primary reference:
91788. D. Aiba and T. Karasawa. 2025. A Late Cretaceous nostoceratid ammonoid, Hyphantoceras orientale (Yabe), exhibiting variation with poorly developed tubercles. Bulletin of the Mikasa City Museum 28:15-22 [M. Clapham/M. Clapham]