Friday September 4, 2026
California Sportfishing Protection Alliance —
The spike-toothed salmon (Oncorhynchus rastrosus) was a roughly 7-foot-long species that lived along the Pacific Coast and Japan five million years ago. This history of this species, particularly its evolution and extinction, reveals that it is difficult to predict the results of climate change.
Data from spike-toothed salmon fossils, reviewed with information from biological studies of modern fish, share clues about how we can protect and restore habitats for extant species. Ensuring there are viable habitats for modern-day species like Chinook salmon could give us more time and populations to understand how and why fish are changing.
The spike-toothed salmon went extinct toward the end of the Early Pliocene, a period that lasted between 5.33 and 2.58 million years ago. It could not survive during a period of global cooling, said Dr. Edward Davis, Professor in the University of Oregon’s Department of Earth Sciences. Davis is also the Condon Fossil Collection Director at the University of Oregon’s Museum of Natural and Cultural History.
“We think it was too big to come up rivers, at a time when the rivers were drying up. It was really the climate that was the deciding factor. It wasn’t predation. Since this species got so big, it had few predators,” said Davis.
The spike-toothed salmon evolved to grow to between 5 feet and 9 feet long because larger females lay more eggs.