Turritella-Tivela 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 A.

• bed-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, brown sandstone and poorly lithified, bioturbated, medium-grained, sandy siltstone

• Inner neritic depth, low current velocities, high sedimentation rate, tropical, shallow subtidal-150 m depth, probably accumated on a delta with shifting facies.
• Brown arkosic sandstone with basaltic rock fragments, grading up into friable, high bioturbated, medium-grained sandy siltstone.. 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 52204: 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.
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium stramineum Gabb 1864 tusk shell
 Gadilida - Gadilidae
"Cadulus gabbi" = Cadulus (Platyschides) gabbi
"Cadulus gabbi" = Cadulus (Platyschides) gabbi Sharp and Pilsbry 1898 tusk shell
Gastropoda
 Heterostropha - Pyramidellidae
Odostomia sp. Fleming 1817 snail
 Trochoidea - Turbinidae
Homalopoma sp. Carpenter 1864 snail
 Opisthobranchia - Cylichnidae
Scaphander washingtonensis Tegland 1933 snail
 Cerithioidea - Thiaridae
 Cerithioidea - Turritellidae
Turritella uvasana Conrad 1855 turret shell
Subspecies: Turritella uvasana olequahensis
 Cerithioidea - Potamididae
 Neotaenioglossa - Trichotropidae
"Crepidula pileum" = Spirocrypta pileum
"Crepidula pileum" = Spirocrypta pileum Gabb 1864 snail
 Neotaenioglossa - Calyptraeidae
Calyptraea diegoana Conrad 1855 slipper shell
 Epitonioidea - Epitoniidae
Acrilla (Ferminoscila) berthiaumei Durham 1937 wentletrap
 Sorbeoconcha - Naticidae
Naticidae indet. Guilding 1834 moon snail
"Neverita reclusiana" = Glossaulax reclusiana Deshayes 1839 moon snail
"Neverita globosa" = Neverita (Neverita) globosa Gabb 1869 moon snail
"Polinices hotsoni" = Polinices (Euspira) hotsoni Weaver and Palmer 1922 moon snail
Polinices nuciformis Gabb 1864 moon snail
Sinum obliquum Gabb 1864 moon snail
 Sorbeoconcha - Cerithiopsidae
 Neogastropoda -
Neogastropoda indet. Thiele 1929 snail
 Neogastropoda - Fasciolariidae
"Whitneyella gabbi" = Perse, "Whitneyella washingtoniana" = Perse washingtoniana
"Whitneyella gabbi" = Perse snail
"Whitneyella washingtoniana" = Perse washingtoniana Weaver 1912 snail
 Neogastropoda - Nassariidae
 Neogastropoda - Buccinidae
Buccinidae indet., "Latirus eocenica" = Nassa eocenica, "Siphonalia sopenahensis" = Siphonalia (Nassicola) sopenahensis, "Siphonalia bicarinata" = Siphonalia (Nassicola) bicarinata
Buccinidae indet. Rafinesque 1815 true whelk
"Latirus eocenica" = Nassa eocenica Weaver 1912 true whelk
"Siphonalia sopenahensis" = Siphonalia (Nassicola) sopenahensis Weaver 1912 true whelk
"Siphonalia bicarinata" = Siphonalia (Nassicola) bicarinata Dickerson 1915 true whelk
 Neogastropoda - Cancellariidae
? Cancellaria sp. Lamarck 1799 snail
 Neogastropoda - Pseudolividae
Calorebama inornata Dickerson 1915 snail
 Neogastropoda - Drilliidae
? Drillia sp. Gray 1838 snail
 Neogastropoda - Clavatulidae
 Neogastropoda - Turridae
Turridae indet., "Hemipleurotoma pluchra" = Gemmula
Turridae indet. Swainson 1840 turrid
"Hemipleurotoma pluchra" = Gemmula turrid
 Neogastropoda - Olividae
Olivella mathewsonii Gabb 1864 olive snail
 Neogastropoda - Ptychatractidae
Exilia clarki Bentson 1940 snail
Exilia dickersoni Weaver 1912 snail
 Neogastropoda - Muricidae
Murex cowlitzensis Weaver 1912 murex snail
Murex sopenahensis Weaver 1912 murex snail
Urosalpinx hannibali Dickerson 1915 murex snail
 Sorbeoconcha - Strombidae
Ectinochilus washingtonensis Clark and Palmer 1923 true conch
 Sorbeoconcha - Cypraeidae
Cypraea sp. Linnaeus 1758 cowry
 Sorbeoconcha - Ficidae
"Ficopsis cowlitzensis" = Priscoficus cowlitzensis
"Ficopsis cowlitzensis" = Priscoficus cowlitzensis Weaver 1912 fig shell
 Vanikoroidea - Eulimidae
Bivalvia
 Nuculanida - Nuculanidae
Nuculanidae indet. Adams and Adams 1858 pointed nut clam
Nuculana washingtoni pointed nut clam
Nuculana vaderensis pointed nut clam
Nuculana "sp. A" Link 1807 pointed nut clam
 Nuculanida - Yoldiidae
Yoldia (Portlandia) duprei Weaver and Palmer 1922 clam
 Mytilida - Mytilidae
Brachidontes (Brachidontes) cowlitzensis Weaver and Palmer 1922 mussel
[entered as Brachydontes (Brachydontes) cowlitzensis]
"Mytilus dichotomus" = Brachidontes (Brachidontes) cooperi Moore 1983 mussel
 Ostreida - Pteriidae
Pteria clarki Weaver and Palmer 1922 pearl oyster
 Ostreida - Ostreidae
Acutostrea idriaensis Gabb 1869 oyster
Subspecies: Acutostrea idriaensis fettkei
 Arcida - Arcidae
Arcidae indet. Lamarck 1809 clam
 Arcida - Glycymerididae
"Glycymeris sagittata" = Glycymeris (Glycymerita) sagittata
"Glycymeris sagittata" = Glycymeris (Glycymerita) sagittata Gabb 1864 clam
 Cardiida - Cardiidae
"Acanthocardia (Schedocardia) brewerii" = Schedocardia brewerii
"Acanthocardia (Schedocardia) brewerii" = Schedocardia brewerii Gabb 1864 cockle
 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 quadratus Gabb 1864 venus clam
Pitar (Lamelliconcha) eocenica Weaver and Palmer 1922 venus clam
Tivelina vaderensis Dickerson 1915 venus clam
Macrocallista sp. Meek 1876 venus clam
 Cardiida - Mactridae
"Spisula packardi" = Pseudocardium packardi
"Spisula packardi" = Pseudocardium packardi Dickerson 1917 clam
 Pholadida - Corbulidae
"Corbula dickersoni" = Corbula (Caryocorbula) dickersoni
"Corbula dickersoni" = Corbula (Caryocorbula) dickersoni Weaver and Palmer 1922 clam
 Pandorida - Pandoridae
Pandora washingtonensis Weaver 1916 clam
 Thraciida - Thraciidae
Thracia dilleri Dall 1898 clam
 Carditida - Crassatellidae
 Carditida - Carditidae
"Venericardia clarki" = Venericardia (Pacificor) clarki
"Venericardia clarki" = Venericardia (Pacificor) clarki Weaver and Palmer 1922 clam
 Myoida -
Myoida indet. Goldfuss 1820 clam