''Acanthodus'' is an extinct genus of

conodont Conodonts, are an extinct group of marine jawless vertebrates belonging to the class Conodonta (from Ancient Greek κῶνος (''kōnos''), meaning " cone", and ὀδούς (''odoús''), meaning "tooth"). They are primarily known from their hard ...

s. ''Acanthodus humachensis'' and ''A. raqueli'' are from then Late Cambrian (late

Furongian The Furongian is the fourth and final epoch and series of the Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding ...

) or early Ordovician (

Tremadocian The Tremadocian is the lowest stage of Ordovician. Together with the later Floian Stage it forms the Lower Ordovician Epoch. The Tremadocian lasted from to million years ago. The base of the Tremadocian is defined as the First appearance datum ...

) of the

Santa Rosita Formation Santa Claus (also known as Saint Nicholas, Saint Nick, Father Christmas, Kris Kringle or Santa) is a legendary figure originating in Western Christian culture who is said to bring gifts during the late evening and overnight hours on Christma ...

in Argentina.New conodont species and biostratigraphy of the Santa Rosita Formation (upper Furongian–Tremadocian) in the Tilcara Range, Cordillera Oriental of Jujuy, Argentina. Fernando J. Zeballo and Guillermo L. Albanesi, Geological Journal, 2013, volume 48, issue 2–3, pages 170–193,

References

External links

* * Conodont genera Cambrian conodonts Ordovician conodonts Furongian first appearances Early Ordovician extinctions Tremadocian Cambrian genus extinctions Ordovician genus extinctions {{Conodont-stub