Metaxytherium

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.

==Discovery and naming== The first remains of Metaxytherium were described in 1822 by Anselme-Gaëtan Demarest as a species of Hippo, H. medius before the genus name Metaxytherium was coined in 1840 by De Christol. Although the type species was initially designated to be M. cuvieri, later publications argued that the two species are synonymous and M. medium thus holds precedence. The grammatical changes of the species name were made to match the rules of the International Code of Zoological Nomenclature (ICZN).