conodont

1. (paleontology) Any of several extinct fish-like chordates having cone-like teeth.Examples: "Remains of conodonts, which may be invertebrates or primitive vertebrates, have also become known from the tuffites and bituminous slates of Monte San Giorgio, which became famous for their fish and marine reptile remains."; "The appearance of tiny teeth elements of an eel-like jawless animal called a conodont, specifically Hindeodus parvus, is the technical herald of the age of the dinosaurs according to the ICS."; "The beginning and the end of the Permian are both defined by the first appearances of particular conodont species."