Evolution of Sirenians: Front

Group includes dugongs and manatees.

Wikipedia: Evolution of Sirenians

Sirenians from Sirenian International

Origin of Sirenians from Edward T Babinski (site is CPU drain)

Dawkins "Greatest Show on Earth" page 172.

As whale is related to hippo, so sirenians to elephant.

Fossil Pezosiren from Eocene. Puijila darwini from Miocene.