UCMP 3148, Stewartville (Eocene of the United States)

Where: Contra Costa County, California (37.9° N, 121.8° W: paleocoordinates 40.6° N, 104.7° 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 52419: 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.
Show authors, comments, and common names
Echinoidea
 Spatangoida - Schizasteridae
Schizaster diabloensis
Schizaster diabloensis Kew 1920 heart urchin
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium cooperi
Dentalium cooperi Gabb 1864 tusk shell
Gastropoda
 Sorbeoconcha - Naticidae
Polinices (Euspira) nuciformis
Polinices (Euspira) nuciformis Gabb 1864 moon snail
Bivalvia
 Nuculanida - Nuculanidae
"Leda gabbi" = Nuculana (Saccella) gabbii
"Leda gabbi" = Nuculana (Saccella) gabbii Conrad 1866 pointed nut clam
 Cardiida - Cardiidae
"Cardium (Protocardium) marysvillensis" = Nemocardium (Nemocardium) linteum
"Cardium (Protocardium) marysvillensis" = Nemocardium (Nemocardium) linteum Conrad 1855 cockle
 Cardiida - Mactridae
"Spisula tejonensis" = Mactromeris tejonensis, "Spisula meganosensis n. sp." = Pseudocardium meganosensis
"Spisula tejonensis" = Mactromeris tejonensis Packard 1916 clam
"Spisula meganosensis n. sp." = Pseudocardium meganosensis Clark and Woodford 1927 clam
 Pholadida - Teredinidae
Teredo sp.
Teredo sp. Linnaeus 1758 clam
 Thraciida - Periplomatidae
Periploma stewartvillensis n. sp.
Periploma stewartvillensis n. sp. Clark and Woodford 1927 clam
Anthozoa
 Scleractinia - Caryophylliidae
Trochocyathus imperialis
Trochocyathus imperialis Nomland 1916 stony coral
[entered as Trochocyathus imperalis]