Eosiren is an extinct genus of sea cow that lived during the Late Eocene (later Priabonian) to Early Oligocene (Rupelian).[1] Several fossils have been found in Egypt. It seems like the species E. abeli were contemporaneous with Protosiren and Eotheroides.[1] like them, Eosiren closely resembled modern sirenians. It differes from them by having somewhat larger innominates and possess thigh bones.[1]

Temporal range: Late Eocene-Oligocene
Eosiren lybica.JPG
Skull of E. libyca .
Scientific classification

Abel, 1913
  • E. abeli
  • E. imenti
  • E. libyca
  • E. stromeri
Drawing of skeleton.
E. libyca and an extant manatee by Charles R. Knight
Size of Eosiren (purple) compared to other Eocene sirenians and a human.

Eosiren was first described by vertebrage paleontologist Charles William Andrews in 1902, who distinguished it from the genus Halitherium due to differences in the teeth and mandible.[2] Later that year, Science published a summary of his findings in a collection on advances in zoopaleontology.[3]


  1. ^ a b c Zalmout I.S. & Gingerich P.D. (2012), “Late Eocene sea cows (Mammalia, Sirenia) from Wadi al Hitan in the western desert of Fayum, Egypt”, University of Michigan Papers on Paleontology No. 37
  2. ^ Andrews, C. W. (1902). "II.—Preliminary Note on some Recently Discovered Extinct Vertebrates from Egypt. (Part III.)" (PDF). Geological Magazine. 9 (7): 291. doi:10.1017/S0016756800181178.
  3. ^ Osborn, H. F. (31 October 1902). "Recent Zoopaleontology". Science. 16 (409): 715. Retrieved 27 January 2021.