Conodont

A peculiar toothlike fossil of many forms, found especially in carboniferous rocks. Such fossils are supposed by some to be the teeth of marsipobranch fishes, but they are probably the jaws of annelids.

small (2 inches long) extinct eellike fish with a finned tail and a notochord and having cone-shaped teeth containing cellular bone; late Cambrian to late Triassic; possible predecessor of the cyclostomes

the tiny fossil cone-shaped tooth of a primitive vertebrate of order Conodonta