Ptychodus

Ptychodus was a large durophagous shark, meaning its diet consisted primarily of hard-shelled organisms. It used its broad, distinctly ridged teeth to crush the shells of prehistoric clams and ammonites. This specialized feeding method set it apart from other predatory marine reptiles of its era.

This extinct genus of shark lived during the Late Cretaceous period. They swam in the ancient oceans millions of years ago, sharing the waters with massive mosasaurs. The genus went extinct right around the time of the Cretaceous-Paleogene mass extinction event.

For over a century, Ptychodus was historically known only from its isolated, ridged teeth, leaving its exact body shape a mystery. Recently, the discovery of complete fossilized skeletons finally allowed scientists to definitively classify the genus. This incredible find revealed that it looked quite different from modern sharks.

Because these sharks lived globally during the Late Cretaceous, their distinctive teeth are found in marine sediment layers around the world. They are relatively common fossils in regions that were once covered by the Western Interior Seaway in North America. Paleontologists use these specific teeth to easily identify the species.