Hagfishes (Myxini) are sometimes referred to as slime eels and occasionally as snot snakes, but they are neither eel nor reptile. They are fishes, but belong to an exclusive group called cyclostomes, ...

Jawless vertebrates once dominated Paleozoic waters, but just two lineages persisted to the present day: lampreys and hagfishes. Living lampreys are a relatively small clade, with just over fifty ...

Today, the opposite is true. Lampreys and hagfish are the only surviving groups of the once-dominant jawless vertebrates. They are among the most primitive living vertebrates, so studying their ...