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 ...

Tiktaalik, the 375-million-year-old fish fossil, is best known for its anatomy suggesting it may have walked out of the water and is also a very popular meme. Sung to the tune of The Killers’ Mr.

A sea lamprey, which has no jaw, has the genetic code to do so, CU researchers find. Photo by Jeff Mitton A half-billion years ago, vertebrates lacked the ability to chew their food. They did not 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 ...