What is "prototherium"

Prototherium is a genus of extinct sirenian related to the dugong. It is known from middle ( Bartonian) and upper Eocene deposits in Italy and Spain.

Three species are now included in the genus, but their phylogenetic relations are not resolved and possibly one of them (Prototherium intermedium) must be excluded. In the same way, relations between Prototherium and other genus are confused and need revision.