(Photo: Wikimedia Commons/Kerin M. Claeson, Brian L. Sidlauskas, Ray Troll, Zabrina M. Prescott, Edward B. Davis)
A prehistoric salmon was found to have tusk-like spikes protruding out of its snout. The spikes were sharp enough to "easily" kill sharks and other large marine animals. The exact purpose of the spikes, which are actually oversized front teeth, is somewhat unclear.
Giant Salmon With Tusk-Like Spikes
The large front teeth resemble fangs, prompting scientists to name the animal the "saber-toothed salmon" or Smilodonichthys rastrosus. However, a new study suggested that it now be called "spike-toothed salmon. Most of the evidence for this finding came from fossils of the teeth discovered isolated from the rest of the cranium.
A fresh image of this ancient salmon has surfaced recently. The front teeth project sideways from the mouth, resembling a warthog's tusks. The most recent study confirms this theory, leading the researchers to propose a new name—"spike-toothed salamo—- based on CT scans of fossils and examination of newly collected remnants over the past few years.
"No other living (or extinct) salmon possesses teeth with such an unusual orientation," said Kerin Claeson, the study's lead author and professor of anatomy at Philadelphia College of Osteopathic Medicine.
The spikes could have served as a weapon to help build nests or defend against predators or other spike-toothed salmon. According to the study, it's possible that the spikes served two goals and had dual functions.
Combined with their enormous body muscles, such spikes would have allowed them to generate amazing strength. Imagine 200 pounds of lateral muscle wielding a one-pound geologist's hammer that has been sharpened. When used with such vigor, these spikes might have easily killed or seriously damaged a rival spike-toothed salmon, shark, dolphin, or sea lion.
"Discoveries like ours show they probably weren't gentle giants," Claeson added.
Since the fish seem to have been filter feeders, it is not believed that the spikes were employed to capture prey. Their time spent in the water probably mirrored that of contemporary Pacific salm. However, they differ in a few ways, one of which is their filter-feeding behavior.
The absence of other large teeth and the presence of spikes indicate that these [prehistoric] fish would have behaved differently in the wild than Pacific salmon do today. These were filter feeders, not like particularly toothy fish that would grab, slice, or eat.
About the Spike-Toothed Salmon
Spike-Toothed Salmon (Oncorhynchus rastrosus), sometimes referred to as the "sabertooth salmon," was an extinct species of salmon that inhabited the Pacific coast of North America. It first emerged in California in the late Miocene and went extinct at some point in the Pleistocene.
It can grow to a maximum length of 2.7 m (9 ft). Due to its size, it is the largest fish ever found in the Salmonidae family, which includes trout and salmon. Adults are thought to have been anadromous, just like their extant counterparts.
In addition to being the largest salmon in the genus Oncorhynchus, this species was named for the two tiny "fangs" that protruded from the snout's tip, giving rise to its synonym and common name. Beyond their fangs, adults of O. rastrosus had larger gill rakers than their smaller, contemporary relatives, which, according to scientists, suggested they ate plankton.
A few million years ago, they inhabited the waters around the coasts of Japan and North America in the North Pacific. It vanished approximately five million years ago.
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