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.

Geology

The Campito Formation is mainly composed of very fine to fine-grained quartzite, with small amounts of siltstone, getting up to thick.

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 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.Montenegro Member: It is the thinnest of the two members, only getting up to 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.

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, and a wealth of ichnogenera, from burrows like Skolithos, to resting traces like Rusophycus.

Arthropoda

Genus	Species	Notes	Images
Fritzaspis	Fritzaspis sp.F. generalisF. ovalis	Fallotaspidoid trilobite.
Amplifallotaspis	A. keni	Fallotaspidoid trilobite.
Profallotaspis	Profallotaspis sp.	Fallotaspidoid trilobite.
Archaeaspis	A. nelsoniA. macropleuron	Fallotaspidoid trilobite.
Cirquella	C. nelsoni	Fallotaspidoid trilobite.
Cambroinyoella	C. wallacei	Fallotaspidoid trilobite.
Fallotaspis	Fallotaspis sp.F. longa	Fallotaspidoid trilobite.
Daguinaspis	Daguinaspis sp.	Fallotaspidoid trilobite.
Repinaella	Repinaella sp.	Fallotaspidoid trilobite.
Eofallotaspis	Eofallotaspis sp.	Fallotaspidoid trilobite.
Nevadia	Nevadia sp.	Nevadiid trilobite.
Judomia	Judomia sp.	Nevadiid trilobite, assignment to genus is very tentative.
Montezumaspis	M. parallelaM. cometes	Holmiid trilobite.
Esmeraldina	E. roweiE. ellipticaE. cometes	Holmiid trilobite. E. cometes was previously identified as Fallotaspis tazemmourtensis.
Holmiella	Holmiella sp.H. millerensis	Holmiid trilobite.
Palmettaspis	P. consortaP. lidensis	Holmiid trilobite.
Grandinasus	G. auricampusG. patulus	Holmiid trilobite.

Lobopodia

Genus	Species	Notes	Images
Microdictyon	Microdictyon sp.	Xenusid lopopod.

Lophotrochozoa

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

Chancelloriidae

Genus	Species	Notes	Images
Allonia	Allonia sp.	Chancelloriid organism.
Chancelloria	Chancelloria sp.	Chancelloriid organism.

Cnidaria

Genus	Species	Notes	Images
Paiutitubulites	P. variabilis	Anthozoan cnidarian.

Porifera (Sponges)

Genus	Species	Notes	Images
Ethmophyllum	Ethmophyllum sp.	Archeocyathid sponge.

Echniodermata

Genus	Species	Notes	Images
Helicoplacus	Helicoplacus sp.	Oblong echinoderm.
Isolated plates	Eocrinoidea	Isolated plates, possibly of eocrinoid origin.

Foraminifera

Genus	Species	Notes	Images
Platysolenites	P. antiquissimus	Agglutinated hyperamminid foraminiferan.

''incertae sedis''

Genus	Species	Notes	Images
Onuphionella	O. durhami	Tubular fossil.
Volborthella	V. titanius	Tubular fossil, originally described as Campitius.

Ichnogenera

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