31 July 2010
Fossil Vertebrate of the Month: Oncorchynchus rastrosus
Salmon are a symbol of the Northwest, and with good reason: not only have they been a staple food for humans for millennia and a hugely important link in regional food chains for much longer, but they have very deep roots here. Go back to the Late Miocene and you would still see salmon in the rivers of Oregon; you would, in fact, see one of the most impressive prehistoric fish ever discovered: Oncorhynchus rastrosus, the sabertooth salmon. The features that gave the fish its common name (and its original genus name, Smilodonichthys) are its enlarged canines which, arresting as they are, are not as unusual as they might seem, as many modern salmon grow large breeding teeth while migrating upstream to spawn. The size of O. rastrosus, though, is unique: at lengths of up to 2 meters, it was a good deal larger than the largest known Chinook salmon and head and shoulders beyond sockeyes, its nearest living relatives. The sabertooth salmon was in the news this last month (both in the paper and on TV) after a team led by the University of Oregon's own Edward Davis performed a CAT-scan on its skull. The result of this research is a series of impressive 3-D reconstructions, which can be viewed in an online exhibit by the U of O Museum of Natural & Cultural History; if you'd rather see the original in person, it will be part of the museum's revamped PaleoLab exhibit opening this month.