The Deseadan (Spanish: Deseadense) age is a period of geologic time (29.0–21.0 Ma) within the Oligocene epoch of the Paleogene to the Early Miocene epoch of the Neogene, used more specifically within the SALMA classification of South America.
It follows the Tinguirirican and precedes the Colhuehuapian age.
[1] The age is named after the Deseado Formation of the Deseado Massif in eastern Patagonia, Argentina.
The Deseadan South American land mammal age (SALMA) is equivalent to the Arikareean in the North American land mammal age (NALMA) and the Harrisonian in the 2000 version of the classification.
It overlaps with the Hsandagolian of Asia and the MP 25 zone of Europe, the Waitakian and the Landon epoch of New Zealand.