Triazeugacanthus

{{Short description|Extinct genus of cartilaginous fishes}}

{{Speciesbox

| fossil_range = {{Geological_age|383.7|376.1|Devonian}}

| image = Triazeugacanthus affinis development.png

| image_caption = Development of the squamation pattern in T. affinis

| genus = Triazeugacanthus

| parent_authority = Miles, 1966

| species = affinis

| authority = Whiteaves, 1887

}}

Triazeugacanthus is an extinct genus of spiny shark from the Devonian of Canada. It contains a single species, Triazeugacanthus affinis.{{cite web|url=https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=226293&is_real_user=1|title=†Triazeugacanthus Miles 1966 (spiny fish)|website=Paleobiology Database}} With total length up to {{convert|5.272|cm|in}}, it is known from multiple ontogenetic stages.{{Cite journal |last1=Chevrinais |first1=Marion |last2=Sire |first2=Jean-Yves |last3=Cloutier |first3=Richard |date=2017-04-12 |title=From body scale ontogeny to species ontogeny: Histological and morphological assessment of the Late Devonian acanthodian Triazeugacanthus affinis from Miguasha, Canada |journal=PLOS ONE |language=en |volume=12 |issue=4 |pages=e0174655 |doi=10.1371/journal.pone.0174655 |issn=1932-6203 |pmc=5389634 |pmid=28403168 |bibcode=2017PLoSO..1274655C |doi-access=free }}