The Spiked Tooth Salmon Swam The Seas Of What Is Now The Pacific Northwest Seven Million Years Ago, Reaching More Than Eight Feet Long With A Pair Of Long, Curved Teeth Jutting Out From Its Top Jaw
Around seven million years ago, a now-extinct species of salmon swam in the waters of what is now the Pacific Northwest.
They weighed up to 400 pounds and reached more than eight feet long, achieving the title of the largest salmon that ever lived.
However, the fish’s massive size isn’t even its most intimidating characteristic. The salmon had a pair of long, curved teeth jutting out from its top jaw.
Previously, scientists thought that these large teeth pointed downward, much like those of a saber-toothed cat.
But new research published in the journal PLOS One has revealed that their teeth actually stuck out sideways like tusks, which has led them to be described as the “spike-toothed salmon.”
The extinct species is also known as Oncorhynchus rastrosus. They were first discovered in fossils in 1972, but the remains did not include the long teeth and upper jaw bones.
So, scientists could only infer that the teeth had pointed down. In 2014, two new O. rastrosus fossils in Oregon were unearthed, and they had nearly complete skulls.
The scientists saw that these salmon had fangs that protruded from the sides of the tips of their snouts. They were also slightly curved like a mustache.
Both male and female members of the species had spikes, which was unusual because, in modern salmon species, only males experience structural changes in their jaws as they mature into adulthood.
SeanPavonePhoto – stock.adobe.com – illustrative purposes only
The ancient salmon might have used the spikes to defend themselves against predators or competitors. Another possibility is that their spiky teeth were used to dig nests in riverbeds.
Researchers have dismissed the idea that O. rastrosus used their spikes to hunt prey because they possess similar features that large modern fish have to filter plankton out of the water, indicating that their main source of food was plankton.
So, how did the species die out? The giant salmon lived during the Miocene and Pliocene epochs when the planet was warmer.
It’s likely that when the oceans cooled, they were outcompeted by larger fish that fed on plankton, which ultimately led to their demise. The last of these creatures disappeared over five million years ago.
Even as global temperatures increase again, we probably won’t see the return of the spike-toothed salmon. The processes that gave rise to their evolution were complex and occurred over millions of years. It’s unlikely that they can be replicated.
Today, their modern relatives are the Chinook salmon, the largest existing species within the genus Oncorhynchus. This salmon measures up to five feet in length.
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