If you're reading this sentence, you might have a fish to thank. Fish were the first animals to evolve jaws. They use their jaws primarily to eat, but also for defense, as tools—such as to burrow or ...

Scientists uncovered a 310-million-year-old fish fossil with a “tongue bite,” teeth on the roof and floor of its mouth that worked like a second jaw. This adaptation, previously thought to have ...

Whole skeleton of Dipterus, an extinct lungfish from the middle Devonian period. Specimen (UMMP 16140) from the University of Michigan Museum of Paleontology. ANN ARBOR—If you're reading this sentence ...