Prehistoric shark food consumption varied by species, environment, and prey availability. Fossil evidence suggests the megalodon (Otodus megalodon) may have consumed up to several tons of food per day, regularly preying on large whales, marine mammals, sea turtles, and other sharks. Other prehistoric sharks such as cretolamna and hybodus ate bony fish, cephalopods, and smaller sharks, with consumption rates depending on prey abundance. These estimates are based on fragmentary fossil evidence and may vary by research methodology.