What is "priscomyzon"

Mouthparts of a modern lamprey]] Priscomyzon riniensis is an extinct lamprey that lived some 360 million years ago during the Famennian ( Late Devonian) in a marine or estuarine environment South Africa. This small agnathan is anatomically similar to the Mazon Creek lampreys, but is some 35 million years older. Its key developments included the first known large oral disc, circumoral teeth and a branchial basket.

Life reconstruction of Priscomyzon riniensis