Nuculana assemblage - Cowlitz Formation (Eocene of the United States)

Where: Lewis County, Washington (46.4° N, 123.0° W: paleocoordinates 47.3° N, 109.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Cowlitz Formation, Bartonian (41.3 - 38.0 Ma)

• Calcareous nannoplankton most precisely age this unit, placing the Cowlitz fauna in nannoplankton zones NP16 and NP17 (Martini, 1971) and upper CP14 (Oklada and Bukry, 1980), which correlates to the late middle Eocene (40-43 Ma) age (Berggren et al., 1992). Molluscan biostratigraphy suggests a "Tejon" stage age or "Cowlitz-Coaldeo" molluscan stage = Middle Eocene. Collection is assigned to the Bartonian=late Middle Eocene. Collection is from stratigraphic unit E.

• bed-level stratigraphic resolution

Environment/lithology: deep-water; poorly lithified, bioturbated, glauconitic, argillaceous, carbonaceous siltstone

• Middle-upper bathyal environment.
• Highly bioturbated, clay-rich siltstone, with an abundance of fine carbon flakes and glauconite pellets. In general outcrop sare mottled gray-green in color, highly bioturbated, poorly consolidated, and deeply weathered.

Size class: macrofossils

Reposited in the UMMP

Collection methods: bulk,

• Collection is presumably reposited in the Museum of Paleontology, University of California collections. Collected in July of 1978 and 1979. Locality has been and continues to be obscured following the May 1980 Mount St Helen's eruption and subsequent landslides and log jams.

Primary reference: E. A. Nesbitt. 1995. Paleoecological anlaysis of molluscan assemblages from the Middle Eocene Cowlitz Formation, southwestern Washington. Journal of Paleontology 69(6):1060-1073 [A. Miller/A. Hendy/A. Hendy]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 52205: authorized by Austin Hendy, entered by Austin Hendy on 01.08.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Identified by E. Nesbitt, based on figures and descriptions in Dickerson (1914, 1915), and Weaver (1943), and Squires (1984, 1989), and there are anumber of new, undescribed species. Specimen counts are based on the greater number of left and right valves for bivalves.
Rhynchonellata
 Terebratulida - Cancellothyrididae
"Rhynchonella washingtoniana" = Terebratulina washingtoniana
"Rhynchonella washingtoniana" = Terebratulina washingtoniana Weaver 1912
Scaphopoda
 Gadilida - Gadilidae
"Cadulus gabbi" = Cadulus (Platyschides) gabbi
"Cadulus gabbi" = Cadulus (Platyschides) gabbi Sharp and Pilsbry 1898 tusk shell
 Dentaliida - Dentaliidae
Dentalium stramineum Gabb 1864 tusk shell
Bivalvia
 Pandorida - Pandoridae
Pandora washingtonensis Weaver 1916 clam
 Thraciida - Thraciidae
Thracia dilleri Dall 1898 clam
 Cardiida - Tellinidae
Tellina "sp. A" Linnaeus 1758 tellin clam
Tellina "sp. B" Linnaeus 1758 tellin clam
 Cardiida -
"Veneroida indet." = Veneroidei
"Veneroida indet." = Veneroidei Gray 1854 clam
 Cardiida - Veneridae
Pitar (Lamelliconcha) eocenica Weaver and Van Winkle Palmer 1922 venus clam
Pitar quadratus Gabb 1864 venus clam
 Arcida - Glycymerididae
"Glycymeris sagittata" = Glycymeris (Glycymerita) sagittata
"Glycymeris sagittata" = Glycymeris (Glycymerita) sagittata Gabb 1864 clam
 Nuculanida - Nuculanidae
Nuculanidae indet. Adams and Adams 1858 pointed nut clam
Nuculana vaderensis pointed nut clam
Nuculana "sp. A" Link 1807 pointed nut clam
Nuculana "sp. C" Link 1807 pointed nut clam
"Nuculana washingtonensis" = Nuculana (Saccella) washingtonensis Weaver 1916 pointed nut clam
Gastropoda
 Opisthobranchiata - Cylichnidae
Scaphander washingtonensis Weaver 1916 snail
 Heterostropha - Pyramidellidae
 Epitonioidea - Epitoniidae
Acrilla (Ferminoscila) berthiaumei Durham 1937 wentletrap
 Sorbeoconcha - Ficidae
"Ficopsis cowlitzensis" = Priscoficus cowlitzensis
"Ficopsis cowlitzensis" = Priscoficus cowlitzensis Weaver 1912 fig shell
 Sorbeoconcha - Cypraeidae
"Nucleolaria cowlitzensis" = Nucleolaria cowlitziana
"Nucleolaria cowlitzensis" = Nucleolaria cowlitziana Groves 1994 cowry
 Neogastropoda -
Neogastropoda indet. Thiele 1929 snail
 Neogastropoda - Turbinellidae
 Neogastropoda - Ptychatractidae
Exilia dickersoni Weaver 1912 snail
 Neogastropoda - Fasciolariidae
Whitneyella gabbi Dickerson 1917 snail
 Neogastropoda - Buccinidae
"Siphonalia bicarinata" = Siphonalia (Nassicola) bicarinata, "Siphonalia sopenahensis" = Siphonalia (Nassicola) sopenahensis
"Siphonalia bicarinata" = Siphonalia (Nassicola) bicarinata Dickerson 1915 true whelk
"Siphonalia sopenahensis" = Siphonalia (Nassicola) sopenahensis Weaver 1912 true whelk
 Neogastropoda - Mitridae
Mitra washingtoniana Weaver 1912 mitre shell
 Neogastropoda - Cancellariidae
 Neogastropoda - Turridae
Turridae indet. Swainson 1840 turrid
 Neogastropoda - Clavatulidae
Turricula ornata, Turricula cowlitzensis, "Hemipleurotoma pulchra" = Surcula evermanni, "Nekewis washingtoniana" = Surcula washingtoniana
"Hemipleurotoma pulchra" = Surcula evermanni Hanna 1924 snail
"Nekewis washingtoniana" = Surcula washingtoniana Weaver 1912 snail
 Neogastropoda - Conidae
Conus vaderensis Weaver and Van Winkle Palmer 1922 cone shell
Conus cowlitzensis Weaver 1912 cone shell
Conus weaveri Dickerson 1915 cone shell
 Neogastropoda - Muricidae
Urosalpinx hannibali Dickerson 1915 murex snail
 Neogastropoda - Cystiscidae
Persicula sp. Schumacher 1817 snail
 Sorbeoconcha - Cassidae
Echinophoria trituberculata Weaver 1912 snail
 Sorbeoconcha - Bursidae
"Ranella washingtoniana" = Bursa washingtoniana
"Ranella washingtoniana" = Bursa washingtoniana Weaver 1912 frog shell
 Sorbeoconcha - Strombidae
Ectinochilus washingtonensis, "Ectinochilus elongata" = Rimella
Ectinochilus washingtonensis Clark and Palmer 1923 true conch
"Ectinochilus elongata" = Rimella true conch
 Sorbeoconcha - Naticidae
Naticidae indet. Guilding 1834 moon snail
Sinum obliquum Gabb 1864 moon snail
"Polinices hotsoni" = Polinices (Euspira) hotsoni Weaver and Palmer 1922 moon snail
Polinices nuciformis Gabb 1864 moon snail
"Neverita globosa" = Neverita (Neverita) globosa Gabb 1869 moon snail
 Neotaenioglossa - Trichotropidae
"Crepidula pileum" = Spirocrypta pileum
"Crepidula pileum" = Spirocrypta pileum Gabb 1864 snail
 Neritoidea - Neritidae
"Nerita cowlitzensis" = Nerita (Theliostyla) triangulata
"Nerita cowlitzensis" = Nerita (Theliostyla) triangulata Gabb 1869 snail