Also known as Nakahashi Bridge

Where: Gunma, Japan (36.3° N, 138.9° E: paleocoordinates 37.9° N, 137.1° E)

• coordinate stated in text

When: Haraichi Formation (Annaka Group), Tortonian (11.6 - 7.2 Ma)

• Haraichi Formation, Annaka Group, latest middle/earliest late Miocene, Serravallian/Tortonian (ca. 11.5 Ma). The Haraichi Formation includes several tuff layers (Takahashi and Hayashi, 2004). The specimen was found in the horizon located stratigraphically between the Kitamura and Baba tuffs. 40Ar/39Ar dating of the tuffs yielded geological ages of 11.79 ± 0.08 Ma (biotite) for the Kitamura tuff and 11.26±0.09 Ma (biotite) and 11.29 ± 0.12 Ma (sanidine) for the Baba tuff (Odin et al., 1997).

Environment/lithology: marine; lithology not reported

Size class: macrofossils

Primary reference: T. Kimura and Y. Hasegawa. 2019. A new species of Kentriodon (Cetacea, Odontoceti, Kentriodontidae) from the Miocene of Japan. Journal of Vertebrate Paleontology 1-93 [M. Uhen/M. Uhen/M. Uhen]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 200052: authorized by Mark Uhen, entered by Mark Uhen on 04.03.2019

Creative Commons license: CC BY (attribution)