Higashi-Tanakura Group Kamitoyo Fm Molluscan Fauna Locality 20 (Miocene of Japan)

Also known as Locality 20

Where: Japan (37.5° N, 140.0° E: paleocoordinates 38.9° N, 138.4° E)

• coordinate based on political unit

• local area-level geographic resolution

When: Kamitoyo Formation (Higashi-Tanakura Group), Late/Upper Miocene (11.6 - 5.3 Ma)

• Higbashi-Tanajura group is a marine representative of the regressive Genjigawa stage

• formation-level stratigraphic resolution

Environment/lithology: marginal marine; lithified, coarse-grained, shelly/skeletal, blue sandstone and gray, blue tuff

• Distributed in northern end of the basin and replaced laterally by medium sandstone and fine sandstone of the Kubota formation at the margin of its distribution area, especially in the southern area.
• Coarse, cross-laminated loose sandstone rich in shell fragments and quartz. A coarse tuff layer with bipiramidal quartz marks the lowermost horizon of the formation at the type locality. Another thin coarse tuff layer is found in the upper part which is bluish-gray colored and pisolite bearing.

Primary reference: Y. Iwasaki. 1970. The Shiobara-type Molluscan Fauna: An ecological analysis of fossil molluscs. Journal of the faculty of science, University of Tokyo, Section 2 17(3):351-444 [A. Miller/K. Bulinski/K. Bulinski]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 52166: authorized by Arnold Miller, entered by Kate Bulinski on 28.07.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

Scaphopoda
 Dentaliida - Dentaliidae
Bivalvia
 Mytilida - Mytilidae
"Mytilus grayanus" = Crenomytilus grayanus
"Mytilus grayanus" = Crenomytilus grayanus Dunker 1853 mussel
 Pectinida - Pectinoidae
"Pecten (Patinopecten) paraplebejus" = Mizuhopecten paraplebejus, "Chlamys kaneharai" = Mimachlamys kaneharai, "Chlamys (Miyagipecten) matsumoriensis" = Miyagipecten matsumoriensis
"Pecten (Patinopecten) paraplebejus" = Mizuhopecten paraplebejus Nomura and Hatai 1936 scallop
Dominant species at locality
"Chlamys kaneharai" = Mimachlamys kaneharai Yokoyama 1926 scallop
"Chlamys (Miyagipecten) matsumoriensis" = Miyagipecten matsumoriensis Masuda 1952 scallop
 Arcida - Glycymerididae