Metaxytherium

Metaxytherium Temporal range: Miocene–Pleistocene PreЄ Є O S D C P T J K Pg N
M. floridanum fossil
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Sirenia
Family:	Dugongidae
Genus:	Metaxytherium de Christol, 1840
species
M. albifontanum Vélez-Juarbe and Domning, 2014 M. arctodites (Aranda-Manteca et al., 1994) M. crataegense (Simpson, 1932) M. floridanum (Hay, 1922) M. krahuletzi (Depéret, 1895) M. medium (Demarest, 1822) (type species) M. serresii (Gervais, 1847) M. subapenninum (Bruno, 1839)

Metaxytherium is an extinct genus of dugong that lived from the Miocene to the . Its remains have been found in Africa, Asia, Europe, North America, and South America.

There are eight species of Metaxytherium recognized as valid: M. albifontanum, M. arctodites, M. crataegense, M. floridanum, M. krahuletzi, M. medium, M. serresii, and M. subapenninum.

The genus Thalattosiren Sickenberg 1928 was once thought to be distinct from Metaxytherium, but is now considered a junior synonym of M. medium.

The relict species M. subapenninum represents the last stage of evolution of Metaxytherium, showing an increase in body size and in tusk size and a rostral reinforcement responding to a long-term climatic cooling. These aquatic herbivores lived in warm coastal waters and inland waterways, feeding on seagrass.Metaxytherium subapenninum lived in the early and late Pliocene of Italy and Spain (age range: 3.6 to 2.588 million years ago). It is the only species of sirenians that lived in the northwestern coasts of the Mediterranean Sea in the Pliocene. It disappeared from the Mediterranean around 3 million years ago because of the progressive climate cooling. Fossils of these dugongs have been found, from the second half of the nineteenth century, in Piedmont, Emilia-Romagna, Liguria and Tuscany.

Metaxytherium lived in coastal waters and inland waterways, and there is evidence that they were preyed on by sharks.

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