New Species of Ancient Toothed Whale Unveiled: Olympicetus thalassodon

A study published in the open access journal PeerJ Life and Environment reveals the discovery of Olympicetus thalassodon, a new species of early toothed whale that inhabited the North Pacific coastline approximately 28 million years ago. This finding contributes to our understanding of the early history and diversification of modern toothed whales, including dolphins and porpoises.

Key Points

  • Olympicetus thalassodon displays unique characteristics, resembling an intermediate form between ancient whales and modern dolphins.
  • The study, led by Dr. Jorge Velez-Juarbe of the Natural History Museum of Los Angeles County, also describes two closely related odontocetes found in the same region.
  • Fossils were collected from the Pysht Formation along the coast of the Olympic Peninsula in Washington State, dating back 26.5–30.5 million years.
  • The newly identified species and its relatives belong to the Simocetidae family, one of the earliest diverging groups of toothed whales.
  • The Pysht Formation boasts an intriguing fossil assemblage, including extinct flightless birds (plotopterids), early seal and walrus relatives (desmostylians), and toothed baleen whales.
  • Differences in body size and dental structure suggest varied prey acquisition and preferences among simocetids.
  • Further investigations are required to determine if these ancient toothed whales possessed echolocation abilities similar to their modern counterparts.


The discovery of Olympicetus thalassodon sheds light on the early evolution and diversity of toothed whales. Dr. Velez-Juarbe’s study contributes valuable insights into the unique characteristics of this ancient species and its relatives, enhancing our understanding of the fascinating history of marine mammals.

The material in this press release comes from the originating research organization. Content may be edited for style and length. Want more? Sign up for our daily email.