Crenatosiren was originally named
"Halitherium" olseni by Rinehart (1976), who described the species from marine deposits of the late Oligocene (Arikareean NALMA)
Parachucla Formation in the
Suwannee River in
Hamilton County, Florida. Domning (1991) eventually recognized the taxon as more derived than the
Halitherium type species and assigned it to the new genus
Crenatosiren, classifying it as a relative of the dugongid
Rytiodus. The genus name is derived from the Latin words
crenatus (meaning 'notched') and
siren. More specimens of
C. olseni were later found in the
Ashley and
Chandler Bridge formations of
South Carolina. == Palaeoecology ==