''Triazeugacanthus'' is an extinct genus of
spiny shark
Acanthodii or acanthodians is an extinct class of gnathostomes (jawed fishes), typically considered a paraphyletic group. They are currently considered to represent a grade of various fish lineages leading up to the extant Chondrichthyes, which ...
from the
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
of Canada. It contains a
single species, ''Triazeugacanthus affinis''. Individuals were 5-6 cm long. Each
fin
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
(besides the caudal fin) contained a stout spine.
References
Acanthodii genera
Devonian fish of North America
Monotypic fish genera
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