Oldest lamprey fossil
In deposits near Grahamstown in South Africa that are 360 million years old, researchers working with Robert Gess from the University of the Witwatersrand in Johannesburg have discovered the oldest known remains of a lamprey . The animal, which is only 4.2 centimeters long, already shows all the characteristics of its modern-day relatives, which are therefore living fossils.
Priscomyzon riniensis, named after prisco (Latin: old) and myzon for lamprey and the Xhosa term Rini for Grahamstown, apparently lived in an estuary – the tidal, funnel-shaped estuary of a river. Compared to today's representatives, its suction mouth, which is surrounded by 14 teeth, seems a bit oversized. However, it cannot be deduced whether the species lived as a parasite.
Since the animals lack jaws, bones and scales, fossil evidence is rare. As recently as June 2006, Chinese researchers reported the discovery of a 125-million-year-old lamprey fossil, which is also almost indistinguishable from today's specimens.
Along with the gingers, the lampreys are among the only surviving agnatha, or jawless vertebrates. About half of today's species live as parasites that attach themselves to other fish with their round mouths and suck their blood. The other half uses the suction mouth to anchor themselves or to transport stones. The animals live in both freshwater and marine water, with some migrating to the sea and returning to inland waters to spawn.