Protosirenidae is an extinct primitive family of the order Sirenia.D. P. Domning, G. J. Heal, and S. Sorbi. 2017. Libysiren sickenbergi, gen. et sp. nov.: a new sirenian (Mammalia, Protosirenidae) from the middle Eocene of Libya. Journal of Vertebrate Paleontology 37(2):e1299158
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.