What are Conodonts?

Conodonts (the animal) are a group of extinct jawless chrodates that ranged from the Cambrian trough the Triassic. The preserved hard parts (conodont elements) are found in a variety of marine rocks. Although less common, soft part impressions are known from several Paleozoic formations (REFERENCES).

Conodont elements are recovered from rock through mechanical disaggregation and chemical digestion methods. 

How are Conodonts Useful?

Conodont Taxonomy

Historically, conodont elements have been given their own species names (form taxonomy). This remains the case today in many instances, including my own work. It has been long understood, however, that more than one form species is present within a given conodont animal species, thus we try to express conodont taxonomy in terms of animal itself, which has led towards more widespread use of multi-element taxonomy, when possible. The most obvious way in which multiple form species are grouped together into a multi-element taxon is the recovery of natural assemblages, but statistical methods are used in some instances...

Phylum Conodonta