Achi news desk-
The artwork and publicity materials showcasing a giant salmon that lived five million years ago were ready to go to promote a new exhibition, when the discovery of two fossilized skulls immediately changed what researchers were know about the fish.
Initial fossil discoveries of the 2.7-metre-long salmon in Oregon in the 1970s were incomplete and led researchers to mistakenly suggest the fish had fang-like teeth.
It was called the “sabre-toothed salmon” and became a sort of mascot for the Museum of Natural and Cultural History at the University of Oregon, said researcher Edward Davis.
But then two skulls were found in 2014.
Davis, a member of the team that found the skulls, says it was only after they returned to the lab that he realized the significance of the discovery that has led to the fish being renamed in a new peer-reviewed study.
“These two skulls were staring at me with sideways teeth,” said Davis, an associate professor in the university’s earth sciences department.
In that position, the tusk-like teeth could not have been used for biting, he said.
“That was certainly a surprising moment,” said Davis, who serves as director of the Condon Fossil Collection at the university’s Museum of Natural and Cultural History.
“I realized that all the artwork and all the publicity materials and bumper stickers and buttons and T-shirts that we had just made two months earlier, for the new exhibition, were all out of date,” he said with a laugh.
Davis is the co-author of the new study in the journal PLOS One, which renames the giant fish the “spiked toothed salmon.”
He says the salmon used the tusk-like beaks for building nests for spawning, and as defense mechanisms against predators and other salmon.
The salmon lived about five million years ago at a time when the Earth was transitioning from warmer to relatively cooler conditions, Davis said.
It’s hard to know exactly why sockeye relatives died out today, but Davis says the cooler conditions would have affected the productivity of the Pacific Ocean and the amount of rain feeding rivers that served as their spawning grounds.
Another co-author, Brian Sidlauskas, says that a fish the size of the spike-toothed salmon must have been targeted by predators such as killer whales or sharks.
“I like to think … it’s almost like a sledgehammer, these salmon swing their head back and forth to stop things that might want to feast on them,” he said.
Sidlauskas says analysis by the paper’s lead author, Kerin Claeson, found that both male and female salmon have the “multifunctional” spike feature.
“That’s part of our reason for hypothesizing that this tooth is multi-functional… It could easily be for digging nests,” he said.
“Think how big the (nest) would have to be for an animal of this size, and then carve it in water which is probably quite shallow; and so having an extra digging tool attached to your head could be very useful.”
Sidlauskas says the giant salmon help researchers understand the boundaries of what’s possible with salmon evolution, but they also capture the human imagination and a sense of wonder about what’s possible on Earth.
“I think it helps us appreciate a little more what we still have, or I hope it does. That animal is no longer with us, but a product of the same biosphere that sustains us.”
This report was first published by The Canadian Press on April 24, 2024.
Brenna Owen, Canadian Press
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