"from Vracon", which is a reference to the Vraconian substage of the Albian stage in which the species was discovered. The species name agassizensis is derived from the name Agassiz and the Latin ensis (from), meaning "from Agassiz", named after Lake Agassiz where the species was discovered. Coincidentally, the lake itself is named in honor of Louis Agassiz. The common name Ginsu shark, originally coined in 1999 by paleontologists Mike Everhart and Kenshu Shimada, is a reference to the Ginsu knife, as the theoretical feeding mechanisms of C. mantelli was often compared with the "slicing and dicing" when one uses the knife. Phylogeny and evolutionCretoxyrhina bore a resemblance to the modern great white shark in size, shape and ecology, but the two sharks are not closely related, and their similarities are a result of convergent evolution. Cretoxyrhina has been traditionally grouped within the Cretoxyrhinidae, a family of lamnoid sharks that traditionally included other genera resulting in a paraphyletic or polyphyletic family. Siverson (1999) remarked that Cretoxyrhinidae was used as a 'wastebasket taxon' for Cretaceous and Paleogene sharks and declared that Cretoxyrhina was the only valid member of the family.Cretoxyrhina contains four valid species: C. vraconensis, C. denticulata, C. agassizensis, and C. mantelli. These species represent a chronospecies. The earliest fossils of Cretoxyrhina are dated about 107 million years old and belong to C. vraconensis. The genus would progress by C. vraconensis evolving into C. denticulata during the Early Cenomanian which evolved into C. agassizensis during the Mid-Cenomanian which in turn evolved into C. mantelli during the Late-Cenomanian. It is notable that C. agassizensis continued until the Mid-Turonian and was briefly contemporaneous with C. mantelli. This progression was characterized by the reduction of lateral cusplets and the increasing size and robustness of teeth. The Late-Albian–Mid-Turonian interval sees mainly the reduction of lateral cusplets; C. vraconensis possessed lateral cusplets in all teeth except for a few in the anterior position, which would gradually become restricted only to the back lateroposteriors in adults by the end of the interval in C. mantelli. The Late Cenomanian–Coniacian interval was characterized by a rapid increase in tooth (and body) size, significant decrease of crown/height-crown/width ratio, and a transition from a tearing-type to a cutting-type tooth form. Tooth size of C. mantelli individuals inside the Western Interior Seaway peaked around 86 Ma during the latest Coniacian and then begins to slowly decline. In Europe, this peak takes