USGS M4667, Smith Grade (Paleocene of the United States)

Where: Santa Cruz County, California (37.0° N, 122.1° W: paleocoordinates 42.2° N, 99.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Locatelli Formation, Danian (66.0 - 61.6 Ma)

• From lower part of formation. Oldest sedimentary sequence in Santa Cruz county; erosion remnants; as much as 240-270m of siltstone is preserved in area; rests unconformably upon crystaline basement - and is overlain unconformably by the Lompico Sandstone and Santa Margarita Sandstone

• bed-level stratigraphic resolution

Environment/lithology: offshore; poorly lithified, micaceous, brown, gray, yellow siltstone

• Nodular olive-gray to pale-yellowish-brown micaceous siltstone; massive arkosic sandstone locally at base

Size class: macrofossils

Reposited in the UCMP

Collection methods: quarrying,

• Also collections at USGS, Menlo Park

Primary reference: J. C. Clark. 1981. Stratigraphy, paleontology, and geology of the Central Santa Cruz Mountains, California Coast Ranges. United States Geological Survey Professional Paper 1168:1-51 [A. Miller/A. Hendy/R. McClees-Funinan]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 37389: authorized by Austin Hendy, entered by Austin Hendy on 14.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Representative for molluscan, echinoid and arthropod taxa; does not include mentioned foraminifera
Bivalvia
 Arcida - Glycymerididae
Glycymeris sp. Da Costa 1778 clam
 Arcida - Cucullaeidae
Cucullaea mathewsonii Gabb 1864 clam
 Ostreida - Pinnidae
Pinna sp. n. sp.
Pinna sp. n. sp. Linnaeus 1758 oyster
 Pholadomyida - Pholadomyidae
 Lucinida - Lucinidae
Lucinoma sp. Dall 1901 clam
 Nuculida - Nuculidae
Acila sp. Adams and Adams 1858 divaricate nutclam
 Protobranchia - Nuculanidae
Nuculana sp. Link 1807 pointed nut clam
Gastropoda
 Ficoidea - Ficidae
 Sorbeoconcha - Turritellidae
Turritella pachecoensis Stanton 1896 turret shell
Turritella infragranulata Gabb 1864 turret shell
Scaphopoda
 Dentaliida - Dentaliidae
Dentalium sp. Linnaeus 1758 tusk shell
Echinoidea
 Cidaroida - Cidaridae
Cidaris martinezensis pencil urchin
 Spatangoida -
Periaster sp. n. sp. heart urchin
 Spatangoida - Paleopneustidae
Pericosmus sp. Agassiz 1847 heart urchin