Sea Cows and Mermaids "From time to time, the fossilized bones of fifteen-million-year-old sea cows erode from the cliffs along the western shore of the Chesapeake Bay in Maryland.....is a stand-alone summary of our present knowledge on the origin and evolution of both sirens and sirenians." Stephen Godfrey Ph.D., Curator of Paleontology, Calvert Marine Museum.