Pungo River deposits produce at least two species of Hammerhead Shark. Sphyrna zygaena (LINNAEUS, 1758) (Smooth Hammerhead) has the larger teeth of the two. The teeth have broad cusps with a slight bend near the tip. There is a prominent and wide nutritive groove. Lower teeth have more narrow, erect cusps. Most specimens have a smooth cutting cutting edges but large teeth may have very fine serrations.

Fig. 1 - Sphyrna zygaena Upper anterio-lateral (top left & right); Upper lateral (bottom left & right); Lower anterio-lateral (middle) Largest specimen 16mm slant height

 
The Scalloped Hammerhead, Sphyrna lewini (GRIFFITH & SMITH, 1834) grows to a similar size as S. zygaena but the teeth are somewhat finer, more erect and narrower than those of S. zygaena. Like S. zygaena large specimens can have very fine serrations.

Fig. 2 - Sphyrna lewini Upper lateral (top left & right); Lower anterior (bottom left & right); Lower lateral (middle) Largest specimen 10mm slant height