Sawfish fossils suggest teeth likely evolved from body scales in ancient fish

Sawfish fossils suggest teeth likely evolved from body scales in ancient fish

Scientists have long debated the origins of teeth. Did they evolve from body scales that migrated into the mouths of ancient vertebrates and became adapted for eating -- an idea known as the 'outside-in' hypothesis? Or did they evolve independent of scales, originating deep within the oral cavity and ultimately mounting onto the jaws -- known as the 'inside-out' hypothesis? A new study provides evidence for the 'outside-in' hypothesis.

Sawfish fossils suggest teeth likely evolved from body scales in ancient fish

Scientists have long debated the origins of teeth. Did they evolve from body scales that migrated into the mouths of ancient vertebrates and became adapted for eating—an idea known as the "outside-in" hypothesis? Or did they evolve independent of scales, originating deep within the oral cavity and ultimately mounting onto the jaws—known as the "inside-out" hypothesis? A new study by scientists at Penn State provides evidence for the "outside-in"

Sawfish fossils suggest teeth likely evolved from body scales in ancient fish

Scientists have long debated the origins of teeth. A new study by scientists at Penn State provides evidence for one hypothesis. According to vertebrate paleontologist Todd Cook, associate professor of biology, Penn State Behrend, the team did not initially set out to contribute to the teeth origin debate.