The Lamnidae are the family of mackerel sharks known as white sharks. They are large, fast-swimming predatory fish found in oceans worldwide, though prefer environments with colder water. The name of the family is formed from the Greek word lamna, which means "fish of prey", and was derived from the Greek legendary creature, the Lamia. These sharks have pointed snouts, spindle-shaped bodies, and large gill openings. The first dorsal fin is large, high, stiff and angular or somewhat rounded. The second dorsal and anal fins are minute. The caudal peduncle has a couple of less distinct keels. The teeth are gigantic. The fifth gill opening is in front of the pectoral fin and spiracles are sometimes absent. They are powerful, heavily built sharks, sometimes weighing nearly twice as much as other sharks of comparable length from other families. Many sharks in the family are among the fastest-swimming fish, although the massive great white shark is slower due to its large size. Genera and species The family contains five living species in three genera and these selected extinct genera and species: Genus †Carchariolamna Hora, 1939 †Carchariolamna heroni Hora, 1939 Genus Carcharodon Smith, 1838 Carcharodon carcharias (Linnaeus, 1758) (great white shark) †Carcharodon caifassii Lawley, 1876 †Carcharodon hubbelli Ehret, Macfadden, Jones, Devries, Foster & Salas-Gismondi, 2012 (Hubbell's white shark) Genus †Corax Agassiz 1843 Genus †Cosmopolitodus Glikman, 1964 †Cosmopolitodus hastalis Agassiz, 1843 (broad-toothed mako) Genus †Carcharomodus †Carcharomodus escheri Agassiz, 1843 Genus Isurus Rafinesque, 1810 Isurus oxyrinchus Rafinesque, 1810 (shortfin mako) Isurus paucus Guitart-Manday, 1966 (longfin mako) †Isurus desori Agassiz, 1843 †Isurus flandricus Leriche, 1910 †Isurus minutus Agassiz, 1843 †Isurus nakaminatoensis Saito, 1961 †Isurus planus Agassiz, 1856 †Isurus praecursor Leriche, 1905 †Isurus rameshi Mehrotra, Mishra & Srivastava, 1973 Genus †Isurolamna Cappetta, 1976 †Isurolamna affinis Casier, 1946 †Isurolamna bajarunasi Glikman & Zhelezko, 1985 †Isurolamna gracilis Le Hon, 1871 †Isurolamna inflata Leriche, 1905 Genus †Karaisurus Kozlov in Zhelezko & Kozlov, 1999 †Karaisurus demidkini Kozlov in Zhelezko & Kozlov, 1999 Genus †Lamiostoma Glikman, 1964 †Lamiostoma belyaevi Glikman, 1964 †Lamiostoma stolarovi Glikman & Zhelezko in Zhelezko & Kozlov, 1999 Genus Lamna Cuvier, 1816 Lamna ditropis Hubbs & Follett, 1947 (salmon shark) Lamna nasus Bonnaterre, 1788 (porbeagle) †Lamna attenuata Davis, 1888 †Lamna carinata Davis, 1888 †Lamna hectori Davis, 1888 †Lamna marginalis Davis, 1888 †Lamna quinquelateralis Cragin, 1894 †Lamna trigeri Coquand, 1860 †Lamna trigonata Agassiz, 1843 Genus †Lethenia Leriche, 1910 †Lethenia vandenbroecki Winkler, 1880 Genus †Macrorhizodus Glikman, 1964 †Macrorhizodus americanus Leriche,