San Nicholas Island (SN-2) (Quaternary of the United States)

Also known as Vedder & Norris (1963) SN-2

Where: Ventura County, California (33.2° N, 119.5° W: paleocoordinates 33.2° N, 119.2° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Unnamed Formation, Quaternary (2.6 - 0.0 Ma)

• Dune sand and fossiliferous marine terrace deposits of Quaternary age. These overlie Eocene strata. Fossils come from seven well-developed wave-cut platforms at altitudes of 25 to 990 feet. Several submerged terraces are present on the shelf adjacent to the island., the lowest being 400 ft below sea-level. Presumably all the terrace platforms on San Nicholas Island were cut later than the middle Pleistocene diastrophism recognized elsewhere in southern California. Terrace platforms are covered with a variety of sediments of marine and non-marine origin and range in thickness from a few inches to many feet.

• bed-level stratigraphic resolution

Environment/lithology: coastal; pebbly, shelly/skeletal, conglomeratic, calcareous sandstone

• Higher emergent terraces may represent wave-abraded platforms that were eroded during eustatic changes in sea level combined with tectonic uplift. The lowest emergent terrace may have been cut during eustatic sea-level changes followed by very slight regional seaward warping. Presumably all the terrace platforms on San Nicholas Island were cut later than the middle Pleistocene diastrophism recognized elsewhere in southern California
• Generally comprise poorly sorted calcareous sand and gravel composed primarily of mollusc shell fragments, echinoid plates and spines, calcareous algae, and bryozoans.

Size class: macrofossils

Collection methods: quarrying,

• Collections made by Vedder et al (1955-1956). Earlier collections by Cooper (1894), and Howard (1955)

Primary reference: J. G. Vedder and R. M. Norris. 1963. Geology of San Nicolas Island, California. United States Geological Survey Professional Paper 369:1-65 [A. Miller/A. Hendy/P. Wagner]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 37948: authorized by Austin Hendy, entered by Austin Hendy on 27.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Comprehensive for invertebrates
 Sessilia - Balanidae
 Arcida - Glycymerididae
"Glycymeris subobsoleta" = Glycymeris (Axinola) septentrionalis
"Glycymeris subobsoleta" = Glycymeris (Axinola) septentrionalis Middendorf 1849 clam
 Pectinida - Pectinoidae
"Chlamys hastatus" = Chlamys (Chlamys) hastata, "Hinnites giganteus" = Crassadoma gigantea
"Chlamys hastatus" = Chlamys (Chlamys) hastata Sowerby 1842 scallop
"Hinnites giganteus" = Crassadoma gigantea Gray 1825 scallop
 Mytilida - Mytilidae
Mytilus californianus Conrad 1837 mussel
 Carditida - Carditidae
"Glans subquadrata" = Glans carpenteri
"Glans subquadrata" = Glans carpenteri Lamy 1922 clam
 Pholadida - Pholadidae
Penitella ? penita Conrad 1837 clam
 Cardiida - Chamidae
Chama arcana Bernard 1976 jewel box
 Cardiida - Veneridae
"Protothaca cf. staminea" = Leukoma staminea, Humilaria cf. perlaminosa, "Irus lamellifer" = Irusella lamellifera, Saxidomus nuttalli, "Transennella tantilla" = Nutricola tantilla, "Petricola carditoides" = Petricola (Petricola) carditoides
"Protothaca cf. staminea" = Leukoma staminea Conrad 1837 venus clam
Humilaria cf. perlaminosa Conrad 1855 venus clam
"Irus lamellifer" = Irusella lamellifera Conrad 1837 venus clam
Saxidomus nuttalli Conrad 1837 venus clam
"Transennella tantilla" = Nutricola tantilla Gould 1853 venus clam
"Petricola carditoides" = Petricola (Petricola) carditoides Conrad 1837 venus clam
 Cardiida - Psammobiidae
 Cardiida - Semelidae
Cumingia californica Conrad 1837 clam
 Cardiida - Cardiidae
"Trachycardium ? quadragenarium" = Trachycardium (Dallocardia) quadragenarium
"Trachycardium ? quadragenarium" = Trachycardium (Dallocardia) quadragenarium Conrad 1837 cockle
 Cardiida - Lasaeidae
"Lasaea cf. cistula" = Lasaea adansoni, "Kellia laperousii" = Kellia suborbicularis
"Lasaea cf. cistula" = Lasaea adansoni Gmelin 1791 clam
"Kellia laperousii" = Kellia suborbicularis Montague 1803 clam
 Thraciida - Thraciidae
"Thracia curta" = Thracia (Ixartia) curta
"Thracia curta" = Thracia (Ixartia) curta Conrad 1837 clam
 Lucinida - Lucinidae
Epilucina californica Conrad 1837 clam
 Patellogastropoda - Lottiidae
Acmaea sp. n. sp. Eschscholtz 1830 limpet
Acmaea digitalis Eschscholtz 1833 limpet
Acmaea scutum Eschscholtz 1833 limpet
Acmaea mitra Eschscholtz 1833 limpet
  - Siphonaliidae
Calicantharus fortis Carpenter 1866 snail
 Neogastropoda - Olividae
"Olivella biplicata" = Olivella (Callianax) biplicata
"Olivella biplicata" = Olivella (Callianax) biplicata Sowerby 1825 olive snail
 Neogastropoda - Columbellidae
 Neogastropoda - Buccinidae
"Searlesia" dira true whelk
 Neogastropoda - Fasciolariidae
 Neogastropoda - Cystiscidae
 Neogastropoda - Mitridae
"Mitra idae" = Mitra (Atrimitra) idae
"Mitra idae" = Mitra (Atrimitra) idae Melville 1893 mitre shell
 Neogastropoda - Muricidae
 Neogastropoda - Turridae
 Neogastropoda - Raphitomidae
 Neogastropoda - Mitromorphidae
Mitromorpha cf. filosa Carpenter 1865 snail
 Neogastropoda - Conidae
"Conus cf. californicus" = Californiconus californicus
"Conus cf. californicus" = Californiconus californicus Reeve 1844 cone shell
 Littorinoidea - Littorinidae
Lacuna cf. carinata Gould 1848 periwinkle
Littorina planaxis Philippi 1847 periwinkle
 Vanikoroidea - Hipponicidae
Hipponix antiquatus Linnaeus 1767 hoof shell
 Vanikoroidea - Eulimidae
 Vermetoidea - Vermetidae
 Calyptraeoidea - Calyptraeidae
Crepidula adunca Sowerby 1824 slipper shell
Crepidula onyx Sowerby 1824 slipper shell
 Rissooidea - Elachisinidae
 Rissooidea - Barleeidae
 Rissooidea - Rissoidae
 Rissooidea - Vitrinellidae
 Truncatelloidea - Caecidae
 Sorbeoconcha - Cerithiidae
Bittium eschrichtii cerith snail
Subspecies: Bittium eschrichtii montereyense
Bittium ? armillatum cerith snail
 Sorbeoconcha - Dialidae
"Diala" marmorea Carpenter 1864 snail
 Pulmonata - Trimusculidae
 Haliotoidea - Haliotidae
 Turbinoidea - Turbinidae
Astraea gibberosa Dillwyn 1817 red turban
 Turbinoidea - Phasianellidae
 Fissurelloidea - Fissurellidae
Diodora aspera Rathke 1833 snail
 Trochoidea - Trochidae
"Pupillaria cf. parcipicta" = Margarites (Pupillaria), Pupillaria cf. optabilis
"Pupillaria cf. parcipicta" = Margarites (Pupillaria) top snail
Pupillaria cf. optabilis Carpenter 1864 top snail
 Trochoidea - Tegulidae
 Neoloricata - Mopaliidae
Mopalia cf. muscosa Gould 1846 chiton
 Camarodonta - Strongylocentrotidae
Strongylocentrotus cf. franciscanus Agassiz 1863 sea urchin
 Scleractinia - Dendrophylliidae
Balanophyllia elegans Verrill 1864 stony coral