UCMP 3580, Los Meganos (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 52431: 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
Gastropoda
 Neotaenioglossa - Calyptraeidae
"Calyptraea (Galerus) calabasasensis" = Calyptraea diegoana
"Calyptraea (Galerus) calabasasensis" = Calyptraea diegoana Conrad 1855 slipper shell
 Cerithioidea - Turritellidae
Turritella merriami
Turritella merriami Dickerson 1913 turret shell
 Sorbeoconcha - Naticidae
Polinices (Euspira) nuciformis, "Polinices (Euspira) hornii" = Polinices hornii
Polinices (Euspira) nuciformis Gabb 1864 moon snail
"Polinices (Euspira) hornii" = Polinices hornii Gabb 1864 moon snail
 Neogastropoda - Buccinidae
Brachysphingus mammilatus
Brachysphingus mammilatus Clark and Woodford 1927 true whelk
 Heterostropha - Pyramidellidae
Turbonilla marshensis n. sp.
Turbonilla marshensis n. sp. Clark and Woodford 1927 snail
Bivalvia
 Nuculanida - Nuculanidae
"Leda gabbi" = Nuculana (Saccella) gabbii
"Leda gabbi" = Nuculana (Saccella) gabbii Conrad 1866 pointed nut clam
 Pholadida - Corbulidae
"Corbula dilatata" = Caryocorbula complicata
"Corbula dilatata" = Caryocorbula complicata Hanna 1924 clam
 Cardiida - Veneridae
Pitar uvasana
Pitar uvasana Conrad 1855 venus clam
Subspecies: Pitaria uvasana marshensis
 Cardiida - Mactridae
"Spisula meganosensis n. sp." = Pseudocardium meganosensis
"Spisula meganosensis n. sp." = Pseudocardium meganosensis Clark and Woodford 1927 clam
 Cardiida - Tellinidae
"Tellina longa" = Tellina (Angulus) longa
"Tellina longa" = Tellina (Angulus) longa Gabb 1864 tellin clam
 Cardiida - Cardiidae
"Cardium (Protocardium) marysvillensis" = Nemocardium (Nemocardium) linteum
"Cardium (Protocardium) marysvillensis" = Nemocardium (Nemocardium) linteum Conrad 1855 cockle
 Lucinida - Lucinidae
"Phacoides meganosensis n. sp." = Miltha (Miltha) meganosensis
"Phacoides meganosensis n. sp." = Miltha (Miltha) meganosensis Clark and Woodford 1927 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