UCMP 3609, east of Mount Diablo (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 52433: authorized by Austin Hendy, entered by Austin Hendy on 05.08.2005, edited by Jonathan Marcot

Creative Commons license: CC BY (attribution)

Taxonomic list

• Identified by Clark and Stewart.
Gastropoda
 Sorbeoconcha - Naticidae
Polinices (Euspira) nuciformis Gabb 1864 moon snail
 Neogastropoda - Drilliidae
Drillia hartleyensis Clark and Woodford 1927 snail
Bivalvia
 Nuculida - Nuculidae
Nucula (Acila) gabbiana Dickerson 1916 nut clam
 Ostreida - Malleidae
Isognomon sp.1 Lightfoot 1786 oyster
 Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758 oyster
 Cardiida - Cardiidae
"Cardium (Pingecardium) hartleyensis" = Acanthocardia (Schedocardia) brewerii hartleyensis
"Cardium (Pingecardium) hartleyensis" = Acanthocardia (Schedocardia) brewerii hartleyensis Clark and Woodford 1927 cockle
 Cardiida - Tellinidae
"Tellina longa" = Tellina (Angulus) longa
"Tellina longa" = Tellina (Angulus) longa Gabb 1864 tellin clam
 Cardiida - Ungulinidae
"Diplodonta cretacea" = Diplodonta (Diplodonta) cretacea
"Diplodonta cretacea" = Diplodonta (Diplodonta) cretacea Gabb 1864 clam
 Cardiida - Mactridae
"Spisula meganosensis n. sp." = Pseudocardium meganosensis
"Spisula meganosensis n. sp." = Pseudocardium meganosensis Clark and Woodford 1927 clam
 Cardiida - Trapezidae
Coralliophaga sp. Blainville 1824 clam
Anthozoa
 Scleractinia - Oculinidae
"Archohelia clarki n. sp." = Petrophyllia clarki2
"Archohelia clarki n. sp." = Petrophyllia clarki2 Vaughan 1927 stony coral