USGS 17445, Yonabaru (Pliocene of Japan)

Where: Okinawa, Japan (26.2° N, 127.7° E: paleocoordinates 26.5° N, 127.2° E)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Yonabaru Formation (Shimajiri Group), Pliocene (5.3 - 2.6 Ma)

• Fossiliferous bed at the base of low hill. Yonabaru Mudstone (now a formation) spans calcareous nannofossil zones CN10b to middle of CN12b and planktonic foram zones PL1 to PL4 (UjiiĆ©, 1994), indicating an age of primarily Pliocene (but ranging from latest Messinian to possibly early Gelasian).

• bed-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, gray, blue, silty, sandy claystone

• The author estimates that the Yonabaru Clay member was deposted in <100 to 300 fathoms of water.
• Bluish to gray silty to sandy clay, commonly with hackly to conchiodial fracture and fine dark-colored laminated to massive sand, weathering brown to gray, and which in places contains large lime indurated concretions of sand. Most macrofossils found in interclated clay/sand beds. Poorly lithified based on description and fossil preservation.

Size classes: macrofossils, mesofossils

Collected by Raymond A. Saplis; reposited in the USNM

Primary reference: G. A. Cooper. 1957. Tertiary and Pleistocene Brachiopods of Okinawa, Ryukyu Islands. United States Geological Survey Professional Paper 314(A):1-20 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 26654: authorized by Arnold Miller, entered by Chad Ferguson on 21.10.2002, edited by Matthew Clapham

Creative Commons license: CC BY (attribution)

Taxonomic list

Rhynchonellata
 Terebratulida - Frenulinidae
Jolonica macneili Cooper 1957
Gastropoda
 Sorbeoconcha - Campanilidae
 Neogastropoda - Costellariidae
? Makiyamaia ? coreanica Adams and Reeve 1850 ribbed mitre
Makiyamaia coreanica Adams and Reeve 1850 ribbed mitre
subspecies: subdelivius
 Neogastropoda - Buccinidae
 Neogastropoda - Fasciolariidae
Granulifusus niponicus Smith 1879 snail
 Neogastropoda - Ancillariidae
"Ancilla (Baryspira) cf. albocallosa" = Amalda (Baryspira)
"Ancilla (Baryspira) cf. albocallosa" = Amalda (Baryspira) snail
 Neogastropoda - Cancellariidae
 Neogastropoda - Drilliidae
 Neogastropoda - Turridae
Micantapex striatotuberculata turrid
species name is listed as: striato-tuberculata
 Neogastropoda - Cochlespiridae
Nihonia shimajiriensis n. sp. MacNeil 1960 snail
 Neogastropoda - Conidae
Conus cf. yabei cone shell
"Conus cf. litteratus" = Conus (Lithoconus) litteratus Linnaeus 1758 cone shell
 Neogastropoda - Volutidae
 Neogastropoda - Muricidae
Chicoreus sp. Monfort 1810 murex snail
 Sorbeoconcha - Naticidae
Natica cf. vitellus Linnaeus 1758 moon snail
 Seguenzioidea - Eucyclidae
Bathybembix sp. Crosse 1892 snail
 Heterostropha - Architectonicidae
"Architectonica maxima" = Architectonica (Architectonica) maxima
"Architectonica maxima" = Architectonica (Architectonica) maxima Philippi 1849 sundial