Selandian Stage, also spelled Seelandian Stage, Encyclopædia Britannica, Inc. Source: International Commission on Stratigraphy (ICS)division of Paleocene rocks, representing all rocks deposited worldwide during the Selandian Age (61.6 million to 59.2 million years ago) of the Paleogene Period (66 million to 23 million years ago). The Selandian Stage is named for marine strata in the Seeland region of Denmark.
The lower boundary of the Selandian Stage is approximately coincident with the first appearance of the foraminiferan (pseudopod-using unicellular organism protected by a test or shell) Morozovella angulata. The upper boundary of the Selandian Stage lies within the zone of the dinoflagellate (single-celled, aquatic organism with two dissimilar flagellae and exhibiting traits of both plants and animals) microfossil Alisocysta margarita. The Selandian Stage overlies the Danian Stage and underlies the Thanetian Stage.