What is "conodont"

Conodont \Co"no*dont\ (k[=o]"n[-o]*d[o^]nt), n. [Gr. kw^nos cone + 'odoy`s, 'odo`ntos, tooth.] (Zo["o]l.) 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.

n. 1 Any of several extinct fishlike chordates that had conelike teeth 2 A microfossil tooth of such an animal

1. n. tiny fossil cone-shaped tooth of the most primitive vertebrate: the conodont

2. small (2 in) 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

Conodonts ( Greek kōnos, " cone", + odont, " tooth") are extinct chordates resembling eels, classified in the class Conodonta. For many years, they were known only from tooth-like microfossils found in isolation and now called conodont elements. Knowledge about soft tissues remains limited. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity.

Conodonts are considered index fossils, fossils used to define and identify geologic periods.