Pliocene Epoch Parapontoporia sternbergi is an extinct species of long-snouted dolphin that lived in the eastern North Pacific during the Pliocene Epoch. This species is distantly related to Pontoporia blainvillei , the living La Platte River or Franciscan river dolphin of coastal Argentina.
Dolphins are cetaceans, members of the whale family.
They are the most diverse mammalian group to adapt to an aquatic existence. Long-nosed dolphin fossil skull. This specimen measures approximately 61 cm. Collection of the San Diego Natural History Museum. In This Region Remains of P. sternbergi were first discovered in Pliocene-age silty sandstones in the Mission Hills community of San Diego, California.