#Xiphactinus of the Pacific!
This lower jaw (dentary) fragment was found by the team @courtenaymuseum on Vancouver Island, British Columbia, Canada. Though this is all that was found, it has the tooth morphology, and robustness, of #Xiphacrinus. It is also of the right aged rocks. Understanding the age of the rocks is an important component of fossil hunting, albeit not one of the easiest tasks.
What did it look like? Take the biggest, meanest looking bony fish (ie. not a shark) that you can think of: #tarpon or #tigerfish leap to my mind. Now make them almost 20’ long and have teeth that stick out from odd angles in the front of the mouth. You are getting closer! I have included artwork and a skeleton for visual assistance.
Xiphactinus is typically found in the a western Interior Seaway, usually in today’s Kansas. Yet this one was found on the West Coast of #Cretaceous Laramidia.
In some ways fish have it easy to migrate. If they are large enough, they can find prey anywhere, presuming tis present, as there are large swaths of ocean with nothing sizable to eat for a big predator.
It could’ve swam from Kansas to Vancouver Isle during times of heightened seas, such as when the poles completely melted of ice in parts of the Cretaceous, when one could swim from the North Pole to the South Pole and not hit land!
Perhaps that’s when many of these marine taxa make it, swimming via the north side of modern North America and ending up where Vancouver Island is today. Keep in mind with continental drift, an inch or so a year over 70 million years means it’s moved a few miles itself. :-)
A few years back a study suggested Xiphactinus may have had the ability to regulate some of its muscles temperature, a limited form of endothermy we see in some big predatory fish like tuna. It might give them an extra burst of speed, or let them go fast a bit longer, each of which is be useful if chasing terrified prey.
Artwork commissioned from the amazing @paleoart_by_g.monroy
Pat Trask on lead vocals :-)
#FossilCrates
Fossil Crates