Yamanouchi (Miocene of Japan)

Where: Gifu, Japan (35.4° N, 137.2° E: paleocoordinates 39.0° N, 134.5° E)

• coordinate stated in text

When: N7 to N8 foram zone, Yamanouchi Member (Akeyo Formation), Burdigalian (20.4 - 16.0 Ma)

• upper part of Zone N7 and lower part of N8 of Blow (1969)

•Planktonic foraminiferal data place the Hiramatsu Member of the Awa Group in zone N7 [132, 133], ranging from 17.5–16.4 Ma [20, 54]; and the Yamanouchi Member of the Ayeko Formation in the upper part of zone N7 and the lower part of zone N8 [134], with zone N8 ranging from 16.4–15.1 Ma [20, 54]. Fission-track dating of a sample from the base of the Yamanouchi Member indicates an age of 17.3 ± 1.4 Ma [135]. Although the termination of zone N8 at 15.1 Ma could imply a partially Langhian range, we here constrain the age of I. laticephalus to the late Burdigalian (17.5–16.0 Ma) based on (i) the confirmed Burdigalian age of MFM 28501; (ii) the fact that the lower boundary of the Yamanouchi Member predates the Burdigalian/Langhian boundary by as much as 1 Ma, or possibly more; and (iii) the fact that the Yamanouchi Member was only correlated with the lower part of zone N8. (Marx & Fordyce, 2015)

• member-level stratigraphic resolution

Environment/lithology: shallow subtidal; siltstone

• nearshore, silty bottom, influenced by subtropical water currents

Size class: macrofossils

Preservation: original phosphate, replaced with phosphate

Collection methods: surface (float), surface (in situ),

Primary reference: T. Kimura and T. Ozawa. 2002. A new cetothere (Cetacea: Mysticeti) from the early Miocene of Japan. Journal of Vertebrate Paleontology 22(3):684-702 [M. Uhen/M. Uhen/M. Uhen]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 46950: authorized by Mark Uhen, entered by Mark Uhen on 27.01.2005, edited by Jason Head

Creative Commons license: CC BY (attribution)

Taxonomic list

Malacostraca
 Decapoda - Hexapodidae
Paeduma sp.2 Rathbun 1897 crab
 Decapoda - Goneplacidae
Carcinoplax antiqua2 Ristori 1889 crab
 Decapoda - Cancridae
"Cancer (Glebocarcinus) itoigawai n. sp." = Anatolikos itoigawai2
"Cancer (Glebocarcinus) itoigawai n. sp." = Anatolikos itoigawai2 Karasawa 1990 crab
 Decapoda - Macropipidae
Parathranites shibatai n. sp.2, "Charybdis (Minohellenus) quinquedentata n. sp." = Minohellenus quinquedentatus2, "Portunites minoensis n. sp." = Minohellenus minoensis2
Parathranites shibatai n. sp.2 Karasawa 1990 crab
"Charybdis (Minohellenus) quinquedentata n. sp." = Minohellenus quinquedentatus2 Karasawa 1990 crab
"Portunites minoensis n. sp." = Minohellenus minoensis2 Karasawa 1990 crab
 Decapoda - Macrophthalmidae
Tritodynamia globosa n. sp.2 Karasawa 1990 crab
Mammalia
 Cetacea - Eurhinodelphinidae
Eurhinodelphis "sp. A"4 Van Beneden and Gervais 1880 toothed whale
 Cetacea - Cetotheriidae
Cetotheriidae indet.3 Brandt 1872 whale
 Cetacea -
Isanacetus laticephalus Kimura and Ozawa 2002 whale
Reptilia
 Squamata - Crotalidae
Trimeresurus sp.1 Lacépède 1804 pitviper