Conodont

Extinct agnathan chordates resembling eels

Conodonts are an extinct group of jawless vertebrates, classified in the class Conodonta. They are primarily known from their hard, mineralised tooth-like structures called "conodont elements" that in life were present in the oral cavity and used to process food. Rare soft tissue remains suggest that they had elongate eel-like bodies with large eyes. Conodonts were a long-lasting group with over 300 million years of existence from the Cambrian to the beginning of the Jurassic. Conodont elements are highly distinctive to particular species and are widely used in biostratigraphy as indicative of particular periods of geological time.

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