 The tawny nurse shark was first described by French naturalist René @-@ <unk> Lesson as <unk> <unk> , based on a 1 @.@ 4 m ( 4 ft 7 in ) long specimen from New Guinea . His short account was published in 1831 in Voyage au tour du <unk> , sur la <unk> La <unk> . A more detailed description , along with an illustration , was published by German naturalist Eduard <unk> in 1837 as Nebrius concolor , based on a specimen from the Red Sea . Both names were retained , often in separate genera ( Ginglymostoma and Nebrius respectively ) , until they were synonymized by Leonard <unk> in 1984 . <unk> recognized that the tooth shape differences used to separate these species were the result of differences in age , with N. concolor representing younger individuals . 
