Cretodus

Prior to 2017, Cretodus was mainly known from isolated teeth. The discovery of a virtually complete skeleton suggests the genus possessed a body similar in form to the modern tiger shark, with a wide head that was equipped with powerful jaws, and a stout body. Growth It is estimated that C. houghtonorum was about long at birth, became sexually mature at 10 to 15 years of age, and reached its maximum lifespan at 51 to 55 years of age. C. crassidens was about long at birth, became sexually mature at 12 to 17 years of age, and reached its maximum life span at 64 years of age. == Paleoecology ==

Cretodus predated on large prey, and is suggested to have specialized in marine turtles, based on inferred stomach contents (a chelonioid turtle) of a specimen of C. crassidens found in Italy. A predator-prey relationship has also been inferred between C. houghtonorum and hybodont sharks based on stomach contents. The distribution of fossils of C. crassidens suggests a largely cosmopolitan distribution and a preference for offshore areas in contrast with other species in the genus (e.g. C. houghtonorum), which preferred shallow water. Within the Western Interior Seaway, Cretodus lived among a number of other genera of shark including Cretoxyrhina, Squalicorax, Ptychodus, Cretalamna, Scapanorhynchus, and hybodont sharks. In order to coexist, these sharks likely practiced resource partitioning, by occupying different regions (e.g. nearshore v.s. offshore) or specializing in different prey items. == Species ==

Shimada & Everhart (2019) attributed the following species to the genus, asserting they were chronospecies belonging to three grades of crown broadness. • Cretodus longiplicatus • Cretodus semiplicatus • Cretodus gigantea • Cretodus houghtonorum • Cretodus crassidens == References ==