Martinichthys is an extinctgenus of plethodidfish from the Cretaceous of North America.[1][2] It is known from the Niobrara Chalk, in which it is exceedingly rare.[3] It is named after one H. T. Martin, who collected the most complete specimen at the time of description.[2]
Two species are known, the short-snouted M. brevis and the long-snouted M. ziphioides; multiple other species previously described have been synonymized with M. ziphioides.[4] With its long rostrum, the genus shows notable morphological convergence with modern billfish and the co-occurring pachycormid fish Protosphyraena, although not to the extent of its close relative, Rhamphoichthys.[5]
