UCMP 3578, east of Marsh Creek (Eocene of the United States)

Where: Contra Costa County, California (37.9° N, 121.7° W: paleocoordinates 40.5° N, 104.5° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Meganos Formation, Ypresian (56.0 - 47.8 Ma)

• "Meganos" faunas represent upper Bulitian and lower Penutian local ages=Ypresian

• bed-level stratigraphic resolution

Environment/lithology: coastal; lithified, fine-grained, pebbly, calcareous sandstone

• Shallow marine coastal siliciclastic environment
• Fine, micaceous sandstone, commonly with small pebbles, thinly beeded near bottom, more massive at top, yellow-brown to gray in color. The massive sandstones near top contain lenses of harded calcareous and fossiliferous sandstones.

Size class: macrofossils

Reposited in the UCMP

Collection methods: quarrying,

• Collected by Clark and Woodford. Collections reposited at UCMP.

Primary reference: B. L. Clark and A. O. Woodford. 1927. The geology and paleontology of the type section of the Meganos Formation (lower Middle Eocene) of California. University of California Publications in Geological Sciences 17(2):63-142 [A. Miller/A. Hendy/P. Wagner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 52429: authorized by Austin Hendy, entered by Austin Hendy on 05.08.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Identified by Clark and Stewart.
Gastropoda
 Cerithioidea - Turritellidae
Turritella meganosensis n. sp. Clark and Woodford 1927 turret shell
 Sorbeoconcha - Cypraeidae
Cypraea sp. Linnaeus 1758 cowry
 Sorbeoconcha - Naticidae
"Polinices (Euspira) hornii" = Polinices hornii Gabb 1864 moon snail
Polinices (Euspira) gesteri Dickerson 1916 moon snail
Polinices (Euspira) nuciformis Gabb 1864 moon snail
 Opisthobranchia - Cylichnidae
"Scaphander cf. costatus" = Scaphander (Mirascapha) costatus
"Scaphander cf. costatus" = Scaphander (Mirascapha) costatus Gabb 1864 snail
Bivalvia
 Nuculanida - Nuculanidae
"Leda gabbi" = Nuculana (Saccella) gabbii Conrad 1866 pointed nut clam
 Mytilida - Mytilidae
"Modiolus (Brachydontes) ornatus" = Brachidontes (Brachidontes) cowlitzensis
"Modiolus (Brachydontes) ornatus" = Brachidontes (Brachidontes) cowlitzensis Weaver and Palmer 1922 mussel
 Arcida - Glycymerididae
"Glycymeris major" = Glycymerita major
"Glycymeris major" = Glycymerita major Stanton 1896 clam
Subspecies: Glycymeris major meganosensis
 Arcida - Arcidae
"Arca hornii n. sp." = Pachecoa hornii
"Arca hornii n. sp." = Pachecoa hornii Gabb 1864 clam
Subspecies: Arca hornii elusa
 Lucinida - Lucinidae
"Phacoides meganosensis n. sp." = Miltha (Miltha) meganosensis, "Phacoides gyrata" = Gibbolucina (Eomiltha) gyrata
"Phacoides meganosensis n. sp." = Miltha (Miltha) meganosensis Clark and Woodford 1927 clam
"Phacoides gyrata" = Gibbolucina (Eomiltha) gyrata Gabb 1864 clam
 Pholadida - Corbulidae
"Corbula dilatata" = Caryocorbula complicata
"Corbula dilatata" = Caryocorbula complicata Hanna 1924 clam
 Cardiida - Mactridae
"Spisula meganosensis n. sp." = Pseudocardium meganosensis
"Spisula meganosensis n. sp." = Pseudocardium meganosensis Clark and Woodford 1927 clam
 Cardiida - Veneridae
Tivela kelloggensis Clark and Woodford 1927 venus clam
Pitaria californica Clark 1918 venus clam
Subspecies: Pitaria californica stewartvillensis
Pitar uvasana Conrad 1855 venus clam
Subspecies: Pitaria uvasana marshallensis
 Cardiida - Ungulinidae
"Diplodonta cretacea" = Diplodonta (Diplodonta) cretacea
"Diplodonta cretacea" = Diplodonta (Diplodonta) cretacea Gabb 1864 clam
 Solenida - Solenidae
"Solen cf. parallelus" = Solena (Plectosolen) parallelus Gabb 1864 clam
 Carditida - Crassatellidae
"Crassatellites meganosensis" = Crassatella meganosensis
"Crassatellites meganosensis" = Crassatella meganosensis Clark and Woodford 1927 clam