Author: Rafinesque, 1810
Diagnostic Features:
Body usually fairly slender. Snout bluntly to acutely conical, rather long; nostrils lateral on snout, situated adjacent to head rim in ventral view; mouth narrowly parabolic; teeth narrow and thick, awl or blade-shaped, with narrow, smooth-edged, more or less flexed cusps and no lateral cusplets; intermediate teeth in upper jaw small, about half height of upper anteriors. First dorsal origin usually behind the pectoral free rear tips; anal origin under or slightly posterior to second dorsal insertion; no secondary keels on base of caudal fin.
Remarks:
The arrangement of the genus Isurus follows the revisions by Guitart Manday (1966) and Garrick (1967).