An extinct species of giant salmon called Oncorhynchus lastrosus They boasted a pair of front teeth that protruded like fangs from the sides of their mouths, according to new research.
Oncorhynchus lastrosus: (A) CT model of the holotype. (B) Holotype seen from the front of the skull, before complete preparation and CT scanning. (C) Artist-rendered male iconic fish skull with accurate spike-tooth configuration. (D) Artist's rendering of a complete female iconic fish with precise spike tooth configuration. Scale bar blocks – 1 cm each.Image credit: Clairson other., doi: 10.1371/journal.pone.0300252.
Oncorhynchus lastrosus It lived along the Pacific coast of North America (California, Oregon, and Washington) about 11 million to 5 million years ago.
This extinct species was first described in the 1970s from fossils discovered in the freshwater Gateway locality of the Madras Formation near the town of Gateway, Jefferson County, Oregon.
The fish was 2.4 to 2.7 meters (7.9 to 8.9 feet) long and weighed, by some estimates, close to 177 kilograms (400 pounds), making it the largest known member of its family. Salmonidae To live forever.
This species migrated from the Pacific Ocean to inland rivers to spawn, much like salmon today. And it was placophagous based on its numerous gill rakes and few small teeth.
but Oncorhynchus lastrosus It had two upper teeth, 2–3 cm (0.8–1.2 in) long.
Initially, paleontologists thought that these oversized teeth were oriented backwards in the mouth, like fangs, mainly because the tooth fossils were found separated from the rest of the skull. was. This led to the common name “saber-toothed tiger.”
However, through new CT scans and various analyses, Oncorhynchus lastrosus Using fossils collected over the years, Professor Kellyn Cresson of the Philadelphia College of Osteopathic Medicine and her colleagues were able to confirm that the fish's teeth did indeed point sideways out of its mouth, like a warthog.
“As a result, this species should be renamed 'spine-toothed salmon,'” the paleontologists said.
“It is unclear exactly what these teeth were used for, but it is likely that they were used for fighting other spiny-toothed salmon, for defense against natural predators, or as tools for digging nests. ”
“It is also possible that the teeth were used for multiple purposes,” the researchers added.
“However, the teeth were probably not used to capture prey. Oncorhynchus lastrosus It is believed that it was a filter feeder that fed on plankton. ”
“We've known for decades that these extinct salmon in Central Oregon were the largest of all time. Discoveries like ours mean they're probably more than just gentle giants. It shows that there was no such thing,” Professor Cresson said.
“The giant spines on the tips of their snouts would have helped them protect themselves from predators, compete with other salmon, and eventually build nests to incubate their eggs.”
“We are pleased to be able to give a new face to the giant spiny salmon and bring knowledge from the Oregon field to the world,” said University of Oregon researcher and director Dr. Edward Davis. Condon Collection, University of Oregon Museum of Natural and Cultural History.
“We also emphasize that females and males alike had huge fang-like teeth. So both sexes were equally terrifying,” said Professor Brian Sidlauskas, curator of fishes at Oregon State University. said.
team's result It was published in the magazine PLoS ONE.
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KM watercress other. 2024. From the saber to the spike: Reconstruction of an ancient giant sexually dimorphic Pacific salmon from a new angle. Oncorhynchus lastrosus (Salmonidae: Salmonini). PLoS ONE 19 (4): e0300252; doi: 10.1371/journal.pone.0300252
Source: www.sci.news
