Protosirenidae
Introduction '''Protosirenidae''' is an extinct primitive family of the order Sirenia.Protosirenids are thought to have been amphibious quadrupeds, meaning that they spent their time both on land and in the water and had four legs.
See also *Dugongidae*Evolution of sirenians*Manatee
References
External links *  ''Protosiren'' at The Paleobiology Database.