Toyora, Dactylioceras helianthoides zone, Locality (3) Kogodani V. 13b3 (Jurassic of Japan)

Where: Yamaguchi, Japan (34.3° N, 131.0° E: paleocoordinates 44.9° N, 138.7° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: Nb Member (Nishinakayama Formation), Early/Lower Toarcian (183.0 - 182.0 Ma)

• 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.

• bed-level stratigraphic resolution

Environment/lithology: marine; pyritic, silty shale

• Lower to Middle Jurassic shallow marine (partly brackish?) clastic deposits

Size class: macrofossils

Primary reference: 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]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 38218: authorized by Martin Aberhan, entered by Sabine Nürnberg on 19.04.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Bivalvia
 Myalinida - Inoceramidae
 Pholadomyida - Pholadomyidae
Goniomya sp. Agassiz 1842 clam
Cephalopoda
 Ammonitida -
Ammonitina indet. Hyatt 1889 ammonite
Aptychi (isolated)
 Ammonitida - Hildoceratidae
 Ammonitida - Dactylioceratidae
 Belemnoida -
Belemnoida indet. Gray 1849 belemnite