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

GenusSpeciesNotesImages
FritzaspisFritzaspis sp.F. generalisF. ovalisFallotaspidoid trilobite.
AmplifallotaspisA. keniFallotaspidoid trilobite.
Profallotaspis Profallotaspis sp.Fallotaspidoid trilobite.
ArchaeaspisA. nelsoniA. macropleuronFallotaspidoid trilobite.
CirquellaC. nelsoniFallotaspidoid trilobite.
CambroinyoellaC. wallaceiFallotaspidoid trilobite.
FallotaspisFallotaspis sp.F. longaFallotaspidoid trilobite.
DaguinaspisDaguinaspis sp.Fallotaspidoid trilobite.
RepinaellaRepinaella sp.Fallotaspidoid trilobite.
EofallotaspisEofallotaspis sp.Fallotaspidoid trilobite.
NevadiaNevadia sp.Nevadiid trilobite.
Judomia Judomia sp.Nevadiid trilobite, assignment to genus is very tentative.
MontezumaspisM. parallelaM. cometesHolmiid trilobite.
EsmeraldinaE. roweiE. ellipticaE. cometes Holmiid trilobite. E. cometes was previously identified as Fallotaspis tazemmourtensis.
HolmiellaHolmiella sp.H. millerensisHolmiid trilobite.
PalmettaspisP. consortaP. lidensisHolmiid trilobite.
GrandinasusG. auricampusG. patulusHolmiid trilobite.

Lobopodia

GenusSpeciesNotesImages
MicrodictyonMicrodictyon sp.Xenusid lopopod.

Lophotrochozoa

GenusSpeciesNotesImages
MicrocornusMicrocornus sp.Lophotrochozoan hyolith.
LadathecaLadatheca sp.Lophotrochozoan hyolith.
ParkulaParkula sp.Lophotrochozoan hyolith.
Hyolithellus Hyolithellus sp.Lophotrochozoan hyolith.
ObolellaO. excelsisObelellid brachiopod.
PelagiellaP. subangulataPelagiellid 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

    GenusSpeciesNotesImages
    AlloniaAllonia sp.Chancelloriid organism.
    ChancelloriaChancelloria sp.Chancelloriid organism.

    Cnidaria

    GenusSpeciesNotesImages
    PaiutitubulitesP. variabilisAnthozoan cnidarian.

    Porifera (Sponges)

    GenusSpeciesNotesImages
    Ethmophyllum Ethmophyllum sp.Archeocyathid sponge.

    Echniodermata

    GenusSpeciesNotesImages
    HelicoplacusHelicoplacus sp.Oblong echinoderm.
    Isolated plates
    Isolated plates, possibly of eocrinoid origin.

    Foraminifera

    GenusSpeciesNotesImages
    Platysolenites
    • P. antiquissimus
    Agglutinated hyperamminid foraminiferan.

    ''incertae sedis''

    GenusSpeciesNotesImages
    OnuphionellaO. durhamiTubular fossil.
    VolborthellaV. titaniusTubular fossil, originally described as Campitius.

    Ichnogenera

    GenusSpeciesNotesImages
    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.