Sea coast west of Ibaruma, Ishigaki-jima Island (Eocene of Japan)

Where: Japan (24.5° N, 124.3° E: paleocoordinates 28.5° N, 122.3° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Miyara Formation, Priabonian (38.0 - 33.9 Ma)

• The Miyara Formation (same as the Miyaragawa Formation) consists essentially of reefal limestone containing Priabonian larger foraminifera such as Nummulites saipanensis, Pellatispira madraszi, and so on.

• group of beds-level stratigraphic resolution

Environment/lithology: shoreface; lithified, pebbly sandstone

• According to Foster (1965): Interbedded conglomerate and sandstones west of Ibaruma contains rock fragments typically 0.6-6 cm, but up to 16 cm in size; along with obscure crossbedding. Material composing the conglomerates was derived locally from the metamorphic rocks of the Ishigaki Group. Likely deposited around the margins of the then-existing island or islands on submarine shelves or floors composed of the metamorphic rocks of the Ishigaki Group.
• Granular to pebbly sandstone

Size class: macrofossils

Collection methods: Repository: National Science Museum, Tokyo

Primary reference: H. Noda, H. Nakagawa, N. Doi and Y. Kikuchi. 2001. First occurrence of Eocene nautilids from the Miyaragawa Formation in Ishigaki-jima Island the Ryukyus, southwest Japan. Bulletin of the National Science Museum, Tokyo, Series C 27:89-100 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 179914: authorized by Matthew Clapham, entered by Matthew Clapham on 03.07.2016

Creative Commons license: CC BY (attribution)

Taxonomic list

Cephalopoda
 Nautilida - Aturiidae
Aturia yokoyamai Nagao 1926 nautiloid
 Nautilida - Nautilidae
Eutrephoceras japonicus Shimizu 1926 nautiloid
Gastropoda
 Trochoidea - Turbinidae
"Lunella miyarensis" = Turbo (Lunella)
"Lunella miyarensis" = Turbo (Lunella) snail
 Opisthobranchia - Cylichnidae
Scaphander sp. Monfort 1810 snail
 Cerithioidea - Turritellidae
 Cerithioidea - Potamididae
Vicarya yabei Kamada 1960 horn snail
 Sorbeoconcha - Naticidae
Euspira sp. Agassiz 1837 moon snail
 Neogastropoda - Buccinidae
Buccinidae indet. Rafinesque 1815 true whelk
 Neogastropoda - Terebridae
Terebra miyarensis auger snail
 Neogastropoda - Volutidae
Bivalvia
 Pectinida - Limidae
Lima sp. Bruguière 1797 file clam
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Cardiida - Veneridae
Veneridae indet. Rafinesque 1815 venus clam