''Helodus'' (from , 'stud' and 'tooth') is an extinct genus of

cartilaginous fish Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fish'', which have skeleto ...

from the Upper Devonian through Lower Permian.Arno Hermann Müller: ''Textbook of paleozoology. Volume III, Vertebrates, Part 1.'' Gustav Fischer Verlag, 1985. While the type species, ''H. simplex'' from the

Late Carboniferous Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

(

Moscovian Moscovian may refer to: *An inhabitant of Moscow, the capital of Russia *Something of, from, or related to Moscow *Moscovian (Carboniferous) The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (strat ...

~ 315 million years ago) of England is known from an articulated specimen, the rest of the species in this genus are known entirely from isolated teeth.Itano, W.M., Lambert, L.L. A new cochliodont anterior tooth plate from the Mississippian of Alabama (USA) having implications for the origin of tooth plates from tooth files. ''Zoological Lett'' 4, 12 (2018). Over twenty species have been attributed to this genus, many of which may be anterior teeth of other cartilaginous fish. This makes ''Helodus'' a wastebasket taxon. For this reason, only the type species can be confidently attributed to this genus until articulated remains of other species are found. ''H. simplex'' was around 30 centimeters (1 foot) long.

References

Carboniferous cartilaginous fish Prehistoric cartilaginous fish genera Taxa named by Louis Agassiz Paleozoic fish of North America {{paleo-cartilaginous-fish-stub