(Header image: (Claeson et al., 2024))
At a Glance
- A recent study revealed new insights into the ancient giant salmon species Oncorhynchus rastrosus, which inhabited the North American Pacific Northwest millions of years ago.
- Contrary to previous beliefs, the study found that the species’ oversized front teeth projected sideways out of the fish’s mouth, resembling those of a warthog. This led to the proposal of renaming the species the “spike-toothed salmon.”
- The purpose of these unique teeth remains uncertain, but researchers speculate that they may have been used for combat, defense against predators, and nest construction rather than for catching prey, as the species was likely a filter-feeder that consumed plankton.
- The study also highlighted sexual dimorphism in mature, breeding individuals of O. rastrosus, with males and females exhibiting distinct differences in certain anatomical features. This led to the species’ renaming as the Spike-Toothed Salmon.
- This research provides valuable insights into the ancient giant salmon. It underscores the significance of bringing knowledge from the field in Oregon to the world, offering a captivating glimpse into the fascinating world of prehistoric marine life.
A recent study published in the open-access journal PLOS ONE has revealed fascinating insights into the ancient giant salmon species, Oncorhynchus rastrosus, which roamed the North American Pacific Northwest millions of years ago. Led by Kerin Claeson from the Philadelphia College of Osteopathic Medicine, the research sheds light on the remarkable features of this colossal fish.
Initially described in the 1970s, O. rastrosus is estimated to have reached a staggering length of up to 2.7 m (8.9 ft), making it the largest member of the Salmonidae family ever discovered. Contrary to previous beliefs that its oversized front teeth pointed backward like fangs, new CT scans and analysis of fossils have revealed that these teeth projected sideways out of the fish’s mouth, resembling those of a warthog. This discovery has led the researchers to propose renaming the species the “spike-toothed salmon.”
While the exact purpose of these unique teeth remains uncertain, the researchers speculate that they may have been used for combat, possibly in battles with other spike-toothed salmon, or as a defense against predators. Additionally, the teeth might have served as tools for nest construction. Notably, it is unlikely that the teeth were used for catching prey, as O. rastrosus is believed to have been a filter feeder that primarily consumed plankton.
Claeson emphasizes, “Discoveries like ours show they probably weren’t gentle giants. These massive spikes at the tip of their snouts would have been useful to defend against predators, compete against other salmon, and ultimately build the nests where they would incubate their eggs.”
The study also highlights the sexual dimorphism in mature, breeding individuals of O. rastrosus, with males and females exhibiting distinct differences in certain anatomical features. This new understanding of the species’ morphology has led to the renaming of O. rastrosus as the Spike-Toothed Salmon, reflecting the multifunctional nature of its distinctive spikes.
The research provides valuable insights into the ancient giant salmon and underscores the significance of bringing knowledge from the field in Oregon to the world, as noted by Edward Davis, associate professor of earth sciences at the University of Oregon. This groundbreaking study offers a captivating glimpse into the fascinating world of prehistoric marine life, captivating the imagination of scientists and enthusiasts alike.
References
- Claeson, K. M., Sidlauskas, B. L., Troll, R., Prescott, Z. M., & Davis, E. B. (2024). From sabers to spikes: A newfangled reconstruction of the ancient, giant, sexually dimorphic Pacific salmon, †Oncorhynchus rastrosus (SALMONINAE: SALMONINI). PLOS ONE, 19(4), e0300252. https://doi.org/10.1371/journal.pone.0300252
- Public Library of Science. (2024, April 24). These giant, prehistoric salmon had tusk-like teeth. Phys.Org; Phys.org. https://phys.org/news/2024-04-giant-prehistoric-salmon-tusk-teeth.html
