ammonites

Tetraspidoceras zone

General information
Lower boundary: equal to 190.7 Ma (see scale)
Upper boundary: before 186.7 Ma (based on Whiteavesi)
Continent: North America
See collections within this interval
See map of collections within this interval
Key correlations
Period: Jurassic
Epoch: Early/Lower Jurassic
Contained within
  • Early/Lower Jurassic
  • Herangi
  • Jurassic
  • Mesozoic
  • Sherman
  • Phanerozoic
    • Previous intervals
  • Plesechioceras harbledownense
  • Asteroceras varians
  • Coroniceras
  • Canadensis
    • Next interval
  • Freboldi
    • Shares top with
  • Imlayi, Whiteavesi
    • Overlaps with
  • Ururoan (189.6 to 175.6 Ma)
  • Pliensbachian (189.6 to 183.0 Ma)
  • Late/Upper Pliensbachian (189.6 to 183.0 Ma)
  • Early/Lower Pliensbachian (189.6 to 183.0 Ma)
  • Spinatum (189.6 to 183.0 Ma)
  • Margaritatus (189.6 to 183.0 Ma)
  • Davoei (189.6 to 183.0 Ma)
  • Ibex (189.6 to 183.0 Ma)
  • Jamesoni (189.6 to 183.0 Ma)
  • Sinemurian (196.5 to 189.6 Ma)
  • Late/Upper Sinemurian (196.5 to 189.6 Ma)
  • Early/Lower Sinemurian (196.5 to 189.6 Ma)
  • Arnioceras arnouldi (196.5 to 189.6 Ma)
  • Raricostatum (196.5 to 189.6 Ma)
  • Oxynotum (196.5 to 189.6 Ma)
  • Obtusum (196.5 to 189.6 Ma)
  • Turneri (196.5 to 189.6 Ma)
  • Semicostatum (196.5 to 189.6 Ma)
  • Bucklandi (196.5 to 189.6 Ma)
  • Aratauran (201.6 to 189.6 Ma)
    • Appears in scale
  • Palfy North American Ammonite Chrons (2000)

    • Interval name: