Isurus planus, also known as the hooked-tooth mako shark or hooked mako shark, is an extinct lamnid that lived during the Miocene epoch from 23 to 5 million years ago. I. planus can be found only in marine deposits on the Pacific Rim, especially the west coast of the United States. Teeth belonging to I. planus can reach lengths of 2.0 in (5.0 cm), and are often found in the Temblor Formation of Bakersfield, California.