Hydrodamalinae is a recently extinct subfamily of the sirenian family Dugongidae. The Steller's sea cow (Hydrodamalis gigas) was hunted to extinction by 1768, while the genus Dusisiren is known from fossils dating from the middle Miocene to early Pliocene. References Notes Sources (PDF) Sirenians Extinct mammals Mammal subfamilies Miocene first appearances Holocene extinctions