Ischnacanthus

Ischnacanthus is an extinct genus of acanthodian jawed fish. It lived from the Pridoli to the Lochkovian. The type species I. gracilis is only known from Lochkovian.

==Discovery and naming== left|thumb|224x224px|Ischnacanthus sp. cast. Early Devonian, [[Mackenzie Mountains, Northwest Territories (Canada). At the Royal Tyrrell Museum of Palaeontology.]] Ischnacanthus was first discovered in 1861 by Egerton, and later assigned to Isnacanthidae by A. S. Woodward in 1891. The type specimen that defines this species is named Ischnacanthus gracilis, and helps outline the Ischnacanthidae family it belongs to. Fossils of this fish were first discovered in Tillywhandland Quarry, Forfar, Scotland.