Parapontoporia sternbergi
Long-snouted Dolphin
Pontoporiidae

Time
Pliocene Epoch

In Our Region
Remains of P. sternbergi were first discovered in Pliocene-age silty sandstones in the Mission Hills community of San Diego, California. The upper jaw of this interesting species contained at least 180 small, needle-like teeth.

Timeline: 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.

The elongated rostrum and small braincases of both Pontoporia and Parapontoporia are features common to all living "river dolphins," including Inia (Amazon River dolphin), Platanista (Ganges River dolphin), and Lipotes (Yangtze River dolphin). This distinctive skull morphology is also seen in many Miocene toothed whales and represents the primitive condition of small-bodied odontocetes (toothed whales).

Dolphins are cetaceans, members of the whale family. Cetaceans, together with sirenians (dugongs and manatees) first evolved during the Eocene Epoch. They are the most diverse mammalian group to adapt to an aquatic existence.