conodont

plural conodonts

1. biologyAny of several extinct fish-like chordates having cone-like teeth.

   The beginning and the end of the Permian are both defined by the first appearances of particular conodont species.

   2022, Thomas Halliday, Otherlands, Penguin, published 2023, page 245

   2 more 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.

   2012, Winand Brinkmann, Kenneth De Baets, editors, Paleontological Museum of the University of Zürich: Exhibition Guide, Paleontological Institute and Museum of the University of Zürich, →ISBN, page 30

   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.

   2018 May 2, Mark Carnall, The Guardian

2. A microfossil tooth of such an animal.