Martinichthys

Martinichthys is an extinct genus of plethodid fish 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]

Martinichthys Temporal range: Coniacian, 87 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	†Tselfatiiformes
Family:	†Plethodidae
Genus:	†Martinichthys McClung, 1926
Species
M. brevis McClung, 1926 M. ziphioides (Cope, 1877)

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]