Miocene sirenians

Metaxytherium is an extinct genus of dugong that lived from the Oligocene until the end of the Pliocene. Fossil remains have been found in Africa, Europe, North America and South America. Generally marine seagrass specialists, they inhabited the warm and shallow waters of the Paratethys, Mediterranean, Caribbean Sea and Pacific coastline. American species of Metaxytherium are considered to be ancestral to the North Pacific family Hydrodamalinae, which includes the giant Steller's sea cow.

Dusisiren is an extinct genus of dugong related to the Steller's sea cow that lived in the North Pacific during the Neogene.

Rytiodus (meaning Rytina, "wrinkled", an old name for Steller's sea cow) is an extinct genus of sirenian, whose fossils have been discovered in France, Europe and Libya.

Bharatisiren is an extinct genus of mammal which existed in what is now India during the early Miocene (Aquitanian) period.

Dioplotherium is an extinct genus of sirenian related to the dugongs, known from Neogene-aged deposits from southern North America.

Miosiren is an extinct genus of manatee from the Early Miocene of southeastern England (Suffolk) and Antwerp, Belgium. thumb|left|M. canhami fossils Two species are recognized, M. canhami and M. kocki.

Nanosiren garciae is an extinct sirenian dugong that lived in warm shallow seas in what is now Venezuela, approximately 11.610—3.6 Ma during the Miocene and Pliocene. The species is listed in the Paleobiology Database, funded by the Australian Research Council.

Potamosiren is an extinct genus of manatee from the Middle Miocene (Laventan) Honda Group of Colombia.

Ribodon is an extinct genus of manatee that lived around South America (Ituzaingó Formation, then described as Entrerriana Formation, Argentina, Solimões Formation, Brazil and Urumaco Formation, Urumaco, Venezuela) during the Tortonian (Mayoan to Huayquerian in the South American land mammal ages). The type species is R. limbatus.