Fastest animals
The fastest land animal is the cheetah, which has a recorded speed of . The peregrine falcon is the fastest bird and the fastest member of the animal kingdom with a diving speed of . The fastest animal in the sea is the black marlin, which has a recorded speed of .
Cretoxyrhina
A study by Ferron (2017) analyzed the relationships between the morphological variables including the skeleton and tail fin of "C. mantelli" and calculated an average cruising speed of and a burst swimming speed of around , making "Cretoxyrhina" possibly one of the fastest sharks known. For comparison, the modern great white shark reaches speeds of up to and the shortfin mako, the fastest extant shark, has been clocked at a speed of .
Although no fossil evidence for it has been found, it is heavily implied that "Cretoxyrhina" was ovoviviparous as all modern mackerel sharks are. In ovovivipary, young are hatched and grow inside a parent's womb while competing against litter-mates through cannibalism such as oophagy or egg eating. As "Cretoxyrhina" inhabited oligotrophic and pelagic waters where predators such as large mosasaurs like "Tylosaurus" and macropredatory fish like "Xiphactinus" were common, it is likely that it also was an r-selected shark, where large numbers of infants are produced to offset high infant mortality rates. Similarly, pelagic sharks such as the great white shark, thresher sharks, mako sharks, porbeagle shark, and crocodile shark produce two to nine infants per litter.