an artifact of preservation. The names "yellow hammerhead" or "golden hammerhead" are used by fishermen in Trinidad for this shark, and the latter was promoted for wider usage by Castro. Another common name for this species is the curry shark. Phylogenetic analyses based on nuclear and mitochondrial DNA have found that the hammerheads with the smallest cephalofoils are the most derived members of their lineage. The closest relative of the smalleye hammerhead appears to be the scoophead (S. media), and the two of them in turn form a clade with the sister species pair of the scalloped bonnethead (S. corona) and the bonnethead (S. tiburo). Description One of the smaller members of its family, the smalleye hammerhead can reach a length of , though is more typical, and a weight of . The body is streamlined and fairly slender. The mallet-shaped cephalofoil is wide and long, with a span measuring 28–32% of the body length; the leading margin forms a broad arch with indentations in the middle and on either side. The cephalofoils of newborns are longer, more arched, and less indented in front than those of adults. The eyes, placed at the ends of the cephalofoils, are proportionately smaller than in other hammerheads and equipped with nictitating membranes (protective third eyelids). The nostrils are positioned just inside of the eyes, each with a well-developed groove running towards the center of the cephalofoil. The mouth is strongly curved, containing on either side 15–16 upper tooth rows and 15–17 lower tooth rows. The teeth have single narrow cusps with smooth or weakly serrated edges, that are angled in the upper jaw and upright in the lower jaw. The first dorsal fin is tall and slightly falcate (sickle-shaped), originating behind the pectoral fin bases; its free rear tip lies over the origin of the pelvic fins. The second dorsal fin is smaller than the first, but still rather large, with a concave, trailing margin. The pelvic fins have nearly straight trailing margins. The anal fin is taller and longer than the second dorsal fin. The caudal fin has a well-developed lower lobe and a notch near the tip of the upper lobe. The dermal denticles are oval with five horizontal ridges leading to marginal teeth. The most distinctive trait of this species is its coloration; the back and dorsal fins are gray to yellowish gray, and the cephalofoil margins, flanks, underside, pectoral