Trisha Shetty (Editor)

Pitkin Formation

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Type
  
Formation

Country
  
United States

Primary
  
Limestone

Underlies
  
Hale Formation

Sub-units
  
none

Region
  
Arkansas

Overlies
  
Fayetteville Shale

The Pitkin Formation is a geologic formation in Arkansas. It preserves fossils dating back to the Carboniferous period.

Contents

Paleofauna

Early work aimed at creating a comprehensive list for all fossils found in the Pitkin Formation was done by Easton in 1943. Unless otherwise stated, all species below can be found in his 'Fauna of the Pitkin Formation.'

Formanifera

  • Endothyra

    • Porifera, Sponges

  • Cliona

    • Scyphozoa

  • Conularia Originally considered to be a gstropod.

    • Blastoidea

  • Pentremites
    • P. laminatus P. platybasis

    Ophiuroidea, Brittle Stars

    This group was originally place under Stelleroidia in early studies.

  • Aganaster
    • A. singulatus
  • Schoenaster

    • Echinoidea, Sea Urchins

  • Archaeocidaris

    • Worms

    Previous studies have grouped these diverse animals into a single, obsolete taxon: Vermes.

  • Spirorbis

    • Bivalvia, Bivalves

    This group was also referred to by another name in earlier studies: Pelecypoda.

    Scaphopoda, Tusk Shells

  • Laevidentalium

    • Cephalopoda

  • Coloceras (see unidentified section)
  • Cravenoceras
    • C. hesperium
  • Cycloceras
    • C. randolphensis C. equoyahensis
  • Dolorthoceras (See unidentified section)
    • D. eurekensis
  • Eoasianites
    • E. globosus
  • Mooreoceras

    • Trilobita

  • Grifithides
    • G. pustulosus
  • Kaskia
    • K. chesterensis
  • Paladin
    • P. mucronatus

    Ostracoda

  • Glyptopleurain
    • G. optina
  • Paraparchites
  • Primitia
    • P. fayettevillensis

    Vertebrata

  • Cladodus
  • Deltodus
  • Petalodus

    • Plantae, Plants

    "Encrusting Algae" has been reported but not assigned to any genus.

    Unidentified

    Following is a list of fossils also found in the Pitkin by Easton in 1943 that have gone unidentified.

  • A "Cup Coral"
  • A member of the genus Pentremites
  • Three species within Agassizocrinus
  • Two species within Scytalocrinus
  • A totally unidentifiable Crinoid
  • Two species of Bellerophon
  • Two species of Gosseletina
  • Two species of Leptoptygma
  • Two Species of Strobeus
  • One species each of Composita and Echinoconchus
  • Two species of Cypricardella
  • Two species of Coloceras, one of which may actually be Leuroceras
  • One species of Dolorthoceras
  • An unnamed shark spine

    • References

    Pitkin Formation Wikipedia
    (Text) CC BY-SA