Heiseinomori athletic field: Spathian, Japan

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

Geography
Country:Japan
Coordinates: 38.7° North, 141.5° East (view map)
Paleocoordinates:4.8° North, 138.8° East (Wright 2013)
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period: Triassic Epoch: Early Triassic
Stage: Olenekian 10 m.y. bin: Triassic 1
Key time interval: Spathian
Age range of interval: 248.6 - 247 m.y. ago
Stratigraphy
Formation:Osawa
Stratigraphic resolution:bed
Stratigraphy comments: The specimen must come from the middle to upper part of the Osawa Formation. But the precise horizon of the belemnite-bearing bed in the Osawa Formation is unknown, because both boundaries of the Hiraiso/Osawa and Osawa/Fukkoshi formations are not exposed near the fossil site. When the preparation work of the athletic field was conducted, many ammonoid specimens were collected from the present fossil site and its southern extension (present-day Heiseinomori athletic field). They are Xenoceltites cf. crenoventrosus Chao, 1959, Nordophiceras sp., Preflorianites utatsuensis Ishibashi, 2006, Inyoites aff. oweni Hyatt and Smith, 1905, Stacheites floweri Kummel, 1969, Arnautoceltites sp., Prenkites cf. timorensis Spath, 1930, and Leiophyllites pitamaha (Diener, 1895) (Educational Committee of Utatsu Town, 1996; Ishibashi, 2006). Due to the presence of Arnautoceltites species and the absence of Columbites, Subcolumbites and Eodanubites species in this fauna, it is most probable that the fossil horizon belongs to the Arnautoceltites Zone (lower part of the upper Osawa Formation: upper Olenekian).
Lithology and environment
Primary lithology: lithified mudstone
Environment:marine indet.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Reason for describing collection:taxonomic analysis
Collection method comments: Repository: Tohoku University Museum (IGPS)
Metadata
Database number:224864
Authorizer:M. Clapham Enterer:M. Clapham
Research group:marine invertebrate
Created:2022-04-07 23:48:46 Last modified:2025-02-22 15:12:02
Access level:the public Released:2022-04-07 23:48:46
Creative Commons license:CC0
Reference information

Primary reference:
81250. S. Niko and M. Ehiro. 2022. Tohokubelus gen. nov., the oldest belemnite from the Olenekian (Lower Triassic) of northeast Japan. Paleontological Research 26:115-123 [M. Clapham/M. Clapham]