 Gavin Naylor's 1992 allozyme analysis found that the finetooth shark is the second-most basal member of the genus next to the blacknose shark ("C. acronotus").Mine Dosay-Akbulut's 2008 study, based on ribosomal DNA, suggested that the closest relative of the finetooth shark is the smalltail shark ("C. porosus"), and that the two species form a clade apart from other "Carcharhinus" species.The body of the finetooth shark is slender and streamlined.