Shitakara Fm - Kushiro Coal Field (Oligocene of Japan)

Where: Japan (43.0° N, 144.4° E: paleocoordinates 44.8° N, 141.7° E)

• coordinate based on nearby landmark

• local area-level geographic resolution

When: Shitakara Formation (Urahoro Group), Early/Lower Oligocene (33.9 - 28.4 Ma)

• STRATIGRAPHIC RELATIONS: From middle of the Urahoro Group, lying between the Yubetsu Fm (Early Oligocene) and the Shakubetsu Formation, also of the Urahoro Group (presumably also Early Oligocene). THICKNESS: Unknown thickness of unit. AGE: Presumably Early Oligocene; from near base of Oligocene in region. STRATIGRAPHIC POSITION: Collection representative of entire formation in local area.

• formation-level stratigraphic resolution

Environment/lithology: marginal marine; lithified, fine-grained, pebbly, gray, conglomeratic, carbonaceous sandstone

• ENVIRONMENT: Non-marine through shallow marine.
• SPECIFIC LITHOLOGY: Gray, poorly sorted, fine-grained sandstone and pebbly to granular conglomerate composed of chert pebbles, with intercalated coal seams. LITHIFICATION: Presumed lithified, on the basis of age, presence of coal, and low diversity of fauna.

Size class: macrofossils

Collection methods: COLLECTOR: Unknown collected, possibly Y. Honda. REPOSITORY: Unknown repository.

Primary reference: Y. Honda. 1986. A Paleogene molluscan fauna from Hokkaido, northern Japan. Paleontological Society of Japan Special Papers 29:3-15 [A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 68894: authorized by Austin Hendy, entered by Austin Hendy on 12.02.2007

Creative Commons license: CC BY (attribution)

Taxonomic list

• COMPLETENESS: Authoritative for Mollusca. NOMENCLATURE: Slightly antiquated, but with consistent use of species level and subgeneric assignments.
unclassified
  -
Gastropoda
 Neotaenioglossa - Calyptraeidae
Crepidula sp. Lamarck 1799 slipper shell
 Cerithioidea - Turritellidae
Turritella sp. Lamarck 1799 turret shell
 Neogastropoda - Buccinidae
Colus sp. Röding 1798 true whelk
Neptunea modestoidea Takeda 1953 true whelk
 Sorbeoconcha - Naticidae
Naticidae indet. Guilding 1834 moon snail
Neverita (Neverita) sp. Risso 1826 moon snail
Neverita (Neverita) asagaiensis Makiyama 1934 moon snail
Bivalvia
 Pectinida - Pectinoidae
Chlamys shitakaraensis Honda 1980 scallop
 Ostreida - Ostreidae
Ostrea eorivularis Oyama and Mizuno 1958 oyster
 Mytilida - Crenellidae
 Mytilida - Mytilidae
Mytilus sp. Linnaeus 1758 mussel
Mytilus mabuchii Oyama and Mizuno 1958 mussel
 Lucinida - Thyasiridae
Conchocele bisecta Conrad 1849 clam
 Thraciida - Periplomatidae
 Thraciida - Thraciidae
Thracia (Thracia) "n. sp." Blainville 1824 clam
 Pholadida - Myidae
Mya (? Arenomya) grewingki Makiyama 1934 softshell clam
INCLUDES: M. (A.) grewingki grewingki and grewingki kusiroensis
 Cardiida - Corbiculidae
Corbicula sp. Megerle 1811 clam
"Geloina cf. takaoi" = Polymesoda (Geloina) clam
 Cardiida - Vesicomyidae
Hubertschenckia ezoensis Yokoyama 1890 clam
 Cardiida - Veneridae
Callista sp. Poli 1791 venus clam
 Cardiida - Mactridae
Mactra sp. Linnaeus 1767 clam
Spisula sp. Gray 1837 clam
 Cardiida - Cardiidae
 Cardiida - Tellinidae
Macoma sp. Leach 1819 tellin clam
 Solenida - Solenidae
Solen "n. sp." Linnaeus 1758 clam
 Carditida - Carditidae
Cyclocardia sp. Conrad 1867 clam
 Nuculanida - Sareptidae
Portlandia (Portlandiella) watasei clam
SUBSPECIES: P. (Portlandiella) watasei
"Yoldia (Yoldia) laudabilis" = Portlandia laudabilis Yokoyama 1924 clam
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium sp. Linnaeus 1758 tusk shell
Bryozoa
  -
Bryozoa indet. Ehrenberg 1831
Thecostraca
 Balanomorpha - Balanidae
Balanus sp. Da Costa 1778 barnacle