see text Triacanthidae, the triplespines or tripodfishes, is a family of marine ray-finned fishes belonging to the order Tetraodontiformes, which also includes the pufferfishes, boxfishes, filefishes and related groups.

Triacanthidae was first proposed as a family in 1859 by the Dutch physician, herpetologist and ichthyologist Pieter Bleeker,[1] and, in 1968, James C. Tyler classified it within the suborder Triacanthoidei alongside the Triacanthodidae.

[2] The 5th edition of Fishes of the World classifies this as suborder of the order Tetraodontiformes.

The genus Acanthopleurus is known from the species A. serratus Agassiz, 1844 and A. collettei Tyler, 1980 of the Oligocene of Glarus canton, Switzerland.

[6] Other fossil triplespine genera include Cryptobalistes, also from Glarus, as well as Protacanthodes from Monte Bolca, Italy.