Fossils belonging to this genus were first found in
Piacenzian (Upper
Pliocene)
strata near
Montopoli in Val d'Arno, a town in
Tuscany (central
Italy). The Italian
paleontologist Giovanni Capellini described the whale in 1876 and attributed it to a new genus and species, establishing the
type species Idiocetus guicciardinii. Some decades later, in 1926, other fossil remains possibly belonging to the genus were discovered from the
Tortonian (Upper
Miocene) of
Japan. ==References==