Interestingly, other early fossils of different turtle species had shells but no beaked jaws. The dawn beak turtle had a beak but no shell, but modern turtles have all of the above.

The fossil shell of Hoplochelys, an extinct genus of aquatic turtle, one of several types of turtle shells collected from sites in Montana and Colorado. Rick Wicker/Denver Museum of Nature and Science ...

A new fossil discovered by researchers might leave fans of turtles a little shell-shocked. A study published in the journal Nature finds a fossil from a turtle roaming Earth 228 million years ago ...

The fossils had clear mandibles, lined with tiny teeth. Set between the jaws was an odd, single tooth, most likely used to help grind food. “It looks like a trident,” Dr. Izquierdo López said.