Toyora, Dactylioceras helianthoides zone, Locality (9) Sakuragauchidani V. 16a: Early Toarcian, Japan

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Pectinida - Oxytomidae
Meleagrinella sp. Whitfield 1855
1 individual
Bivalvia - Ostreida - Bakevelliidae
Gervillia sp. Defrance 1820
3 individuals
Bivalvia - Myalinida - Inoceramidae
1 individual
Cephalopoda - Ammonoida
Ammonoida indet. (Haeckel 1866)
43 individuals
Cephalopoda - Phylloceratida - Phylloceratidae
2 individuals
Cephalopoda - Ammonitida
Ammonitina indet. Hyatt 1889
2 individuals
Aptychi (isolated)
Cephalopoda - Ammonitida - Dactylioceratidae
40 individuals
Cephalopoda - Ammonitida - Lytoceratidae
1 individual
sp. A
Cephalopoda - Ammonitida - Hildoceratidae
2 individuals
7 individuals
11 individuals
see common names

Geography
Country:Japan State/province:Yamaguchi
Coordinates: 34.3° North, 131.0° East (view map)
Paleocoordinates:45.2° North, 155.7° East (Wright 2013)
Basis of coordinate:estimated from map
Geographic resolution:small collection
Time
Period: Jurassic Epoch: Early Jurassic
Stage: Toarcian 10 m.y. bin: Jurassic 3
Key time interval: Early Toarcian
Age range of interval: 184.2 - 182.9 m.y. ago
Stratigraphy
Geological group:Toyora Formation:Nishinakayama Member:Nb
Local section:(9) Sakuragauchidani V. Local bed:16a
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: Locality belongs to the Dactylioceras helanthoides zone. The Nishinakayama Fm attains about 300m in maximum thickness, and is lithostratigraphically subdivided into three members, namely Na, Nb (black shales with intercalations of fine sandstone; 160m thick), and Nc in upward sequence.
Lithology and environment
Primary lithology: silty "shale"
Environment:marine indet.
Geology comments: Lower to Middle Jurassic shallow marine (partly brackish?) clastic deposits
Taphonomy
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection
Collection size:113 individuals
Reason for describing collection:paleoecologic analysis
Metadata
Database number:38208
Authorizer:M. Aberhan Enterer:S. Nurnberg
Modifier:S. Nurnberg Research group:marine invertebrate
Created:2004-04-19 08:02:10 Last modified:2025-02-22 15:12:02
Access level:the public Released:2004-07-19 08:02:10
Creative Commons license:CC0
Reference information

Primary reference:
10253. K. Tanabe. 1991. Early Jurrasic Macrofauna of the Oxygen-Depleted Epicontinental Marin Basin in the Toyora Area, West Japan. Saito Ho-on Kai Special Publication 3:147-161 [M. Aberhan/S. Nurnberg/P. Wagner]