Campito Formation

The Campito Formation is a geologic formation in the Last Chance Range, California, and Esmeralda County, Nevada. It preserves fossils dating back to the Cambrian period.

Campito Formation
Stratigraphic range: Lower Cambrian PreꞒ Ꞓ O S D C P T J K Pg N [1]
White Mountains mousetails, growing on substrate within the Campito Formation
Type	Formation
Sub-units	See: Members
Underlies	Poleta Formation[2]
Overlies	Deep Spring Formation[2]
Thickness	0–3,500 ft (0–1,067 m)[3]
Lithology
Primary	Quartzite
Other	Siltstone, Sandstone
Location
Region	California, Nevada
Country	United States

Geology

The Campito Formation is mainly composed of very fine to fine-grained quartzite, with small amounts of siltstone, getting up to 3,500 ft (1,100 m) thick.^[3]

Members

The formation is split into two distinct members, which are as follows, in ascending age:

• Andrews Mountain Member: It is the thickest of the two members, getting up to 2,800 ft (850 m) thick. It is composed of olive-gray or greenish-gray very fine to fine grained silty quartzitic sandstone or quartzite and interbedded layers of dark-greenish-gray siltstones, which weather to a greenish-black or just black. The quartzite layers are composed of sub-angular very fine to fine grains of quartz, feldspar and other metallic minerals, all set within a muscovite, chlorite, and biotite.^[3]

• Montenegro Member: It is the thinnest of the two members, only getting up to 1,000 ft (300 m) thick. It is composed of dark-greenish-gray and greenish-gray siltstone composed of a mixture of quartz, muscovite, and chlorite. The siltstone is evenly laminated to thin-bedded. There are also commonly occurring archeocyathid-bearing limestone beds in the upper sections of the member.^[3]

Paleobiota

The Campito Formation contains a number of fossils, most of which are found within the Montenegro Member. They range from archeocyathid sponges like Ethmophyllum, to arthropod trilobites like Nevadia,^[3] and a wealth of ichnogenera, from burrows like Skolithos, to resting traces like Rusophycus.^[4]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Arthropoda

Genus	Species	Notes	Images
Fritzaspis[5]	Fritzaspis sp. F. generalis F. ovalis	Fallotaspidoid trilobite.
Amplifallotaspis[5]	A. keni	Fallotaspidoid trilobite.
Profallotaspis (?)[5]	Profallotaspis (?) sp.	Fallotaspidoid trilobite.
Archaeaspis[6]	A. nelsoni A. macropleuron	Fallotaspidoid trilobite.
Cirquella[6]	C. nelsoni	Fallotaspidoid trilobite.
Cambroinyoella[6]	C. wallacei	Fallotaspidoid trilobite.
Fallotaspis[3][7][8][9]	Fallotaspis sp. F. longa	Fallotaspidoid trilobite.
Daguinaspis[3]	Daguinaspis sp.	Fallotaspidoid trilobite.
Repinaella[9][5][5]	Repinaella sp.	Fallotaspidoid trilobite.
Eofallotaspis[9]	Eofallotaspis sp.	Fallotaspidoid trilobite.
Nevadia[3]	Nevadia sp.	Nevadiid trilobite.
Judomia (?)[3]	Judomia (?) sp.	Nevadiid trilobite, assignment to genus is very tentative.
Montezumaspis[10]	M. parallela M. cometes	Holmiid trilobite.
Esmeraldina[3][10][9]	E. rowei E. elliptica E. cometes (?)	Holmiid trilobite. E. cometes was previously identified as Fallotaspis tazemmourtensis.[9]
Holmiella[10]	Holmiella sp. H. millerensis	Holmiid trilobite.
Palmettaspis[10]	P. consorta P. lidensis	Holmiid trilobite.
Grandinasus[10]	G. auricampus G. patulus	Holmiid trilobite.

Lobopodia

Genus	Species	Notes	Images
Microdictyon[11][12]	Microdictyon sp.	Xenusid lopopod.

Lophotrochozoa

Genus	Species	Notes	Images
Microcornus[12]	Microcornus sp.	Lophotrochozoan hyolith.
Ladatheca[9]	Ladatheca sp.	Lophotrochozoan hyolith.
Parkula[12]	Parkula sp.	Lophotrochozoan hyolith.
Hyolithellus (?)[12]	Hyolithellus (?) sp.	Lophotrochozoan hyolith.
Obolella[13]	O. excelsis	Obelellid brachiopod.
Pelagiella[12]	P. subangulata	Pelagiellid mollusc.
Nisusia (?)[13][9]	Nisusia (?)sp.	Kutorginid brachiopod.
Sabellidites (?)[9]	Sabellidites (?) sp.	Tubular fossil.
Brachiopod indet.[13]	???	Indeterminate brachiopod, most likely an internal mold, possibly a poorly preserved Nisusia (?)sp. specimen, or another kutorginid brachiopod.
Obelellid molds[9]	???	Molds of obelellid brachiopods.

Chancelloriidae

Genus	Species	Notes	Images
Allonia[12]	Allonia sp.	Chancelloriid organism.
Chancelloria[12]	Chancelloria sp.	Chancelloriid organism.

Cnidaria

Genus	Species	Notes	Images
Paiutitubulites[14]	P. variabilis	Anthozoan cnidarian.

Porifera (Sponges)

Genus	Species	Notes	Images
Ethmophyllum (?)[1]	Ethmophyllum (?) sp.	Archeocyathid sponge.

Echniodermata

Genus	Species	Notes	Images
Helicoplacus[7]	Helicoplacus sp.	Oblong echinoderm.
Isolated plates[15]	Eocrinoidea (?)	Isolated plates, possibly of eocrinoid origin.

Foraminifera

Genus	Species	Notes	Images
Platysolenites[7]	P. antiquissimus	Agglutinated hyperamminid foraminiferan.

incertae sedis

Genus	Species	Notes	Images
Onuphionella[8]	O. durhami	Tubular fossil.
Volborthella[16]	V. titanius	Tubular fossil, originally described as Campitius.[7]

Ichnogenera

Genus	Species	Notes	Images
Cruziana[4]	Cruziana sp.	Trails.
Planolites[4]	Planolites sp.	Burrows.
Helminthopsis[4]	Helminthopsis sp.	Feeding trails.
Belorhaphe[4]	Belorhaphe sp.	Burrows.
Cochlichnus[4]	Cochlichnus sp.	Burrows.
Scolicia[4]	Scolicia sp.	Burrows.
Rusophycus[4]	R. didymus R. radwanskii	Resting trace of trilobites.
Bergaueria[4]	Bergaueria sp.	Resting trace of cnidarians.
Zoophycus[4]	Zoophycus sp.	Polychaete feeding traces.
Arthrophycus[4]	Arthrophycus sp.	Polychaete trace.
Teichichnus[4]	Teichichnus sp.	Feeding trace.
Treptichnus[4]	Treptichnus sp.	Burrow, originally described as Phycodes.
Diplichnites[4]	Diplichnites sp.	Arthropod trackways.
Skolithos[4]	Skolithos sp.	Burrows.

See also

• Earth sciences portal
• United States portal
• Paleontology portal

• List of fossiliferous stratigraphic units in Nevada
• Paleontology in Nevada