Ischyrhiza

Ischyrhiza is an extinct genus of sawfish from the Late Cretaceous and Early Paleogene, belonging to the primitive Batoidea family Sclerorhynchidae. Fossils of the genus have been found in Canada, the United States, the Aguja Formation of Mexico, the Tamayama Formation of Japan, the Dukamaje Formation of Niger, the El Molino Formation of Bolivia, the Quiriquina Formation of Chile, and the Chota Formation of Peru.[1]