The characteristic shovel- or bonnet-shaped head makes this hammerhead the easiest to identify. Body moderately compact; head flattened, spade-shaped front margin of head not lobed without nasal grooves, the anterior margin of the head is evenly rounded between the eyes; mouth arched; mouth corners posterior to oculonarial expansion. The frontal teeth have erect, smooth-edged cusps, while subsequent teeth have oblique cusps; the outermost teeth of the lower jaw are modified into flat crushers. First dorsal fin high, originating slightly posterior to base of pectoral fin; second dorsal with rear lobe not well developed, higher and shorter than anal one; eyes separated from nasal grooves by a distance of 1.5 times diameter of eye. Some are dark brown in the lateral dorsal region, lighter in ventral region while others are gray or greensih gray above and paler below. Average size is 70-100 cm (28-39 in.) Maximum size is about 110 cm (43 in.) These are the smallest of family Sphyrnidae (Cortes and Parsons,1996).

Range mass: 3 to 4 kg.

Average mass: 0.0035 kg.