With terrifyingly sharp teeth arranged around a circular mouth, lampreys look about as primitive a vertebrate as you could imagine. But a new study finds that the animals have a surprising similarity ...

Strange sea creatures called ctenophores have a fused nerve net where scientists expected to see synapses. Did they evolve their nervous system separately from other animals? When you purchase through ...

The sympathetic nervous system was thought to have evolved with jawed vertebrates. But lampreys—jawless, parasitic fish that suck out the blood of their hosts—have a simple one, per recent research.