San Nicholas Island (SN-5) (Quaternary of the United States)

Also known as Vedder & Norris (1963) SN-5

Where: Ventura County, California (33.2° N, 119.6° 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: general faunal/floral analysis

PaleoDB collection 37945: authorized by Austin Hendy, entered by Austin Hendy on 27.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Comprehensive for invertebrates
unclassified
  -
Maxillopoda
 Sessilia - Balanidae
Polychaeta
  -
Bivalvia
 Mytilida - Mytilidae
Mytilus californianus Conrad 1837 mussel
 Cardiida - Veneridae
"Transennella tantilla" = Nutricola tantilla
"Transennella tantilla" = Nutricola tantilla Gould 1853 venus clam
 Cardiida - Semelidae
Cumingia californica Conrad 1837 clam
 Cardiida - Cardiidae
"Clinocardium nuttallii" = Clinocardium (Clinocardium) nuttallii
"Clinocardium nuttallii" = Clinocardium (Clinocardium) nuttallii Conrad 1837 cockle
 Cardiida - Lasaeidae
"Lasaea cf. cistula" = Lasaea adansoni
"Lasaea cf. cistula" = Lasaea adansoni Gmelin 1791 clam
 Lucinida - Lucinidae
Epilucina californica Conrad 1837 clam
Gastropoda
 Patellogastropoda - Lottiidae
Acmaea sp. n. sp. Eschscholtz 1830 limpet
Acmaea mitra Eschscholtz 1833 limpet
Acmaea pelta Eschscholtz 1833 limpet
  - Siphonaliidae
Calicantharus fortis Carpenter 1866 snail
 Triphoroidea - Cerithiopsidae
Cerithiopsis sp. Hanley 1849 snail
 Neogastropoda - Olividae
"Olivella biplicata" = Olivella (Callianax) biplicata
"Olivella biplicata" = Olivella (Callianax) biplicata Sowerby 1825 olive snail
 Neogastropoda - Columbellidae
Mitrella cf. carinata snail
Subspecies: Mitrella carinata gausapata
 Neogastropoda - Buccinidae
"Searlesia" dira true whelk
 Neogastropoda - Fasciolariidae
Barbarofusus ? arnoldi Cossmann 1903 snail
 Neogastropoda - Mitridae
"Mitra idae" = Mitra (Atrimitra) idae
"Mitra idae" = Mitra (Atrimitra) idae Melville 1893 mitre shell
 Neogastropoda - Muricidae
 Neogastropoda - Mangeliidae
Mangelia cf. variegata Carpenter 1864 snail
 Neogastropoda - Conidae
"Conus cf. californicus" = Californiconus californicus
"Conus cf. californicus" = Californiconus californicus Reeve 1844 cone shell
 Neogastropoda - Pseudomelatomidae
 Littorinoidea - Littorinidae
 Vermetoidea - Vermetidae
 Calyptraeoidea - Calyptraeidae
Crepidula cf. onyx Sowerby 1824 slipper shell
 Rissooidea - Barleeidae
 Rissooidea - Rissoidae
Alvania sp. n. sp. Risso 1826 snail
 Truncatelloidea - Caecidae
 Sorbeoconcha - Cerithiidae
Bittium eschrichtii cerith snail
Subspecies: Bittium eschrichtii montereyense
 Sorbeoconcha - Dialidae
"Diala" cf. marmorea Carpenter 1864 snail
 Haliotoidea - Haliotidae
 Turbinoidea - Turbinidae
Astraea cf. gibberosa Dillwyn 1817 red turban
 Turbinoidea - Phasianellidae
 Fissurelloidea - Fissurellidae
Diodora cf. aspera Rathke 1833 snail
 Trochoidea - Tegulidae
Polyplacophora
 Neoloricata - Mopaliidae
Mopalia muscosa Gould 1846 chiton
Echinoidea
 Camarodonta - Strongylocentrotidae
Strongylocentrotus cf. franciscanus Agassiz 1863 sea urchin
Anthozoa
 Scleractinia - Dendrophylliidae
Balanophyllia elegans Verrill 1864 stony coral