Dorsal spine of Orthacanthus adamas from the Upper Freeport Coal (Carboniferous) of Linton, Ohio. The spine is about 71 mm long. Disclaimer: AAAS and EurekAlert! are not responsible for the ...

Until recently, Orthacanthus gracilis could have been considered the "John Smith" of prehistoric shark names, given how common it was. Three different species of sharks from the late Paleozoic Era ...

The species died almost 300 million years ago. The Orthacanthus was a freshwater shark native to Europe and North America.

Within the fossils, there were loads of juvenile shark teeth. Scientists think that this species, Orthacanthus, lived in oily waters in swamps off the coast of Europe and North America ...