Middle Paleocene

The Selandian is in the geologic timescale an age or stage in the Paleocene. It spans the time between 61.6 and 59.2 Ma. It is preceded by the Danian and followed by the Thanetian. Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "Middle Paleocene".

The Selandian was introduced in scientific literature by Alfred Rosenkrantz in 1924. It is named after the Danish island of Zealand (Danish: Sjælland).

The base of the Selandian is close to the boundary between biozones NP4 and NP5. It is slightly after the first appearances of many new species of the calcareous nannoplankton genus Fasciculithus (F. ulii, F. billii, F. janii, F. involutus, F. tympaniformis and F. pileatus) and close to the first appearance of calcareous nannoplankton species Neochiastozygus perfectus. At the original type location in Denmark the base of the Selandian is an unconformity. The official GSSP was established in the Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern Spain.

The top of the Selandian (the base of the Thanetian) is laid at the base of magnetic chronozone C26n.

The Selandian stage overlaps with the lower part of the Tiffanian North American Land Mammal Age, the Peligran, Tiupampan and lower Itaboraian South American Land Mammal Ages and part of the Nongshanian Asian Land Mammal Age. It is coeval with the lower part of the Wangerripian stage from the Australian regional timescale.

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