San Nicholas Island (SN-6) (Quaternary of the United States)

Also known as Vedder & Norris (1963) SN-6

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: general faunal/floral analysis

PaleoDB collection 37944: authorized by Austin Hendy, entered by Austin Hendy on 27.03.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Comprehensive for invertebrates
unclassified
  -
Echinoidea
 Camarodonta - Strongylocentrotidae
Strongylocentrotus cf. franciscanus Agassiz 1863 sea urchin
Polyplacophora
 Neoloricata - Mopaliidae
Mopalia muscosa Gould 1846 chiton
Gastropoda
 Patellida - Lottiidae
Acmaea sp. n. sp., Acmaea mitra, "Acmaea ? limatula" = Lottia limatula, "Acmaea digitalis" = Lottia digitalis
Acmaea sp. n. sp. Eschscholtz 1830 limpet
Acmaea mitra Eschscholtz 1833 limpet
"Acmaea ? limatula" = Lottia limatula Carpenter 1864 limpet
"Acmaea digitalis" = Lottia digitalis Eschscholtz 1833 limpet
 Trochoidea - Turbinidae
"Astraea gibberosa" = Pomaulax gibberosa, "Homalopoma carpenteri" = Homalopoma (Homalopoma) luridum
"Astraea gibberosa" = Pomaulax gibberosa Dillwyn 1817 red turban
"Homalopoma carpenteri" = Homalopoma (Homalopoma) luridum Dall 1885 snail
 Trochoidea - Phasianellidae
"Tricolia cf. pulloides" = Eulithidium pulloides
"Tricolia cf. pulloides" = Eulithidium pulloides Carpenter 1865 snail
 Trochoidea - Trochidae
"Tegula funebralis" = Chlorostoma funebrale, "Tegula brunnea" = Chlorostoma brunnea, "Pupillaria cf. optabilis" = Lirularia optabilis, Calliostoma cf. ligatum
"Tegula funebralis" = Chlorostoma funebrale Adams 1855 top snail
"Tegula brunnea" = Chlorostoma brunnea Philippi 1849 top snail
"Pupillaria cf. optabilis" = Lirularia optabilis Carpenter 1864 top snail
Calliostoma cf. ligatum Gould 1849 top snail
 Lepetellida - Fissurellidae
Diodora aspera Rathke 1833 snail
 Neotaenioglossa - Calyptraeidae
Crepidula onyx Sowerby 1824 slipper shell
Crepidula adunca Sowerby 1824 slipper shell
 Cerithioidea - Cerithiidae
"Bittium eschrichtii" = Neostylidium eschrichtii
"Bittium eschrichtii" = Neostylidium eschrichtii Middendorff 1849 cerith snail
Subspecies: Bittium eschrichtii montereyense
 Sorbeoconcha - Rissoidae
"Alvania purpurea" = Alvinia purpurea
"Alvania purpurea" = Alvinia purpurea Dall 1871 snail
 Sorbeoconcha - Barleeiidae
Amphithalamus cf. tenuis Bartsch 1911 snail
 Sorbeoconcha - Vermetidae
Petaloconchus complicatus Dall 1908 worm shell
 Sorbeoconcha - Hipponicidae
Hipponix tumens Carpenter 1864 hoof shell
Antisabia panamensis Adams 1852 hoof shell
 Neogastropoda - Olividae
"Olivella biplicata" = Callianax biplicata
"Olivella biplicata" = Callianax biplicata Sowerby 1825 olive snail
 Neogastropoda - Mitridae
"Mitra cf. idae" = Mitra (Atrimitra) idae
"Mitra cf. idae" = Mitra (Atrimitra) idae Melville 1893 mitre shell
 Neogastropoda -
"Barbarofusus cf. arnoldi" = Harfordia arnoldi
"Barbarofusus cf. arnoldi" = Harfordia arnoldi Cossmann 1903 snail
 Neogastropoda - Nassariidae
"Nassarius cf. perpinguis" = Caesia perpinguis
"Nassarius cf. perpinguis" = Caesia perpinguis Hinds 1844 snail
 Neogastropoda - Pseudomelatomidae
Pseudomelatoma torosa Gabb 1864 snail
 Neogastropoda - Conidae
"Conus californicus" = Californiconus californicus
"Conus californicus" = Californiconus californicus Reeve 1844 cone shell
 Neogastropoda - Mangeliidae
"Mangelia cf. nitens" = Cythara (Mangelia), "Mangelia variegata" = Tenaturris variegata
"Mangelia cf. nitens" = Cythara (Mangelia) snail
"Mangelia variegata" = Tenaturris variegata Carpenter 1864 snail
 Sorbeoconcha - Littorinidae
"Lacuna unifasciata" = Lacuna (Epheria) unifasciata, "Littorina cf. scutulata" = Littorina (Littorina) scutulata
"Lacuna unifasciata" = Lacuna (Epheria) unifasciata Carpenter 1857 periwinkle
"Littorina cf. scutulata" = Littorina (Littorina) scutulata Gould 1849 periwinkle
 Sorbeoconcha - Procerithiidae
"Bittium cf. attenuatum" = Lirobittium attenuatum
"Bittium cf. attenuatum" = Lirobittium attenuatum Carpenter 1864 snail
 Heterostropha - Pyramidellidae
  -
"Daphnella fuscoligata" = Clathromangelia fuscoligata
"Daphnella fuscoligata" = Clathromangelia fuscoligata Dall 1871 snail
Bivalvia
 Carditida - Carditidae
"Glans subquadrata" = Glans carpenteri
"Glans subquadrata" = Glans carpenteri Lamy 1922 clam
 Lucinida - Lucinidae
Epilucina californica Conrad 1837 clam
 Cardiida - Veneridae
"Transennella tantilla" = Nutricola tantilla
"Transennella tantilla" = Nutricola tantilla Gould 1853 venus clam
 Cardiida - Semelidae
Cumingia cf. californica Conrad 1837 clam
 Cardiida - Neoleptonidae
Bernardina ? bakeri Dall 1910 clam
 Mytilida - Mytilidae
Mytilus californianus Conrad 1837 mussel
Thecostraca
 Balanomorpha - Tetraclitidae
Tetraclita ? squamosa barnacle
Subspecies: Tetraclita squamosa rubescens