Wikipedia
Hemipristis
Hemipristis is a genus of weasel shark, family Hemigaleidae. It contains one extant species, the snaggletooth shark (H. elongata), as well as several extinct species.
Hemipristis has two distinct type of teeth in each section of its jaw. The ones on the upper jaw act like knives, cutting through the flesh of the prey, while the pointed ones on the bottom act like forks, spearing the prey and holding it down. Because this shark was poorly studied in the past and its top and bottom jaw teeth differ to such a great degree, its top and lower jaw teeth were assigned to a separate genus in the past.