ammonites

Alexandrian age/stage

General information
Lower boundary: equal to 443.7 Ma (based on Rhuddanian)
Upper boundary: before 436 Ma (based on Aeronian)
Continent: North America
See collections within this interval
See map of collections within this interval
Key correlations
Period: Silurian
Epoch: Llandovery
10 million year bin: Silurian 1
Contained within
  • Sherman
  • Paleozoic
  • Phanerozoic
    • Previous intervals
  • Ordovician
  • Late/Upper Ordovician
  • Ashgill
  • Hirnantian
  • Kosov
  • Porkuni
  • Gamach
  • Cincinnatian
  • Gamachian
  • Richmondian
  • Harju
  • Kosovian
  • Bolindian
  • Qiantianjiang
  • Aijiashan
  • Wufeng
  • Xiaoxita
  • Shikou
  • Chientangkiangian
  • Ashgillian
  • late Late Ordovician
    • Next intervals
  • Telychian
  • Woolhope
  • Lower Visby
  • Tonawandan
  • Chesnokovka
  • Polaty
    • Shares base with
  • Cowleigh Park, Juuru, Litenschichten, Llandovery, Niagaran, Rhuddanian, Silurian
    • Shares top with
  • Aeronian
    • Overlaps with
  • Clinton (439.0 to 426.2 Ma)
  • Wych (439.0 to 428.2 Ma)
  • Ontarian (439.0 to 428.2 Ma)
  • Adavere (439.0 to 428.2 Ma)
  • Syrovaty (439.0 to 428.2 Ma)
  • Raikkula (443.7 to 436.0 Ma)
  • Medina (443.7 to 436.0 Ma)
  • Vtorye Utesy (443.7 to 436.0 Ma)
    • Appears in scale
  • Harland Silurian of North America (1990)

    • Interval name: