co·no·dont 
(kōnə-dŏnt′, kŏnə-)
(kōnə-dŏnt′, kŏnə-)n.
1. Any of various small marine chordates of the group Conodonta of the Paleozoic Era and the Triassic Period, preserved primarily in the form of their conelike teeth.
2. A fossil tooth of this chordate. Conodonts are the most widespread Paleozoic microfossils and are important for biostratigraphic indexing.
[Greek kōnos, cone; see kō- in the Appendix of Indo-European roots + -ODONT.]