Carcharhinus falciformis, the Silky shark, is a medium/large-sized (to 3.5m) circumtropical species. They are deep-water reef-associated/epipelagic usually in waters less than 500m. The species feeds mainly on teleosts (particularly tuna), but also cephalopods and crustaceans. (Ref. Garrick 1982, Compagno 1984, Compagno et al 2005, and FishBase.org.)

The dentition is cutting-clutching in design with moderately broad distally inclined uppers and narrow upright lowers. Teeth (generally) number 15 per quadrate (plus parasymphyseals)² displaying gradational and dignathic heterodonty.

The upper teeth are characterized by large coarse shoulder (basal crown) serrations that result in a distinct notch when they meet the triangular main cusp (apical portion of crown) with its finer serrations (ref. fig. left); the notch is displayed along the mesial and (more so) distal edges. The roots are well-developed with a strong nutrient groove.

Lower teeth are rather indistinct but vary positionally. Using the above extant specimen (fig. ) as an example: Anterior-most positions (fig. right) tend to have an erect cusp with incomplete cutting-edges (finely serrate) and limited to the apical half of the crown; in addition the shoulders of these positions begin to display shoulder serrations commencing from the lateral margins and expanding in more distal positions (by the eighth position (fig. left), the shoulders are nearly completely serrate). In the 10th position, the cusp shows a more distal inclination, the "bulged" appearance of the apical cutting-edge is lost and their serrations disappear to the naked-eye. By the 12th position, the mesial cutting edge is complete (root to apex) and the distal distinguished only by a notch (fig. right). This particular file-set may or may not be typical of the species.

Lee Creek Perspective

The Carcharhinus falciformis tooth-design is fairly common in the Miocene of the Chesapeake and Carolinas. Müller (1999: 49, pl 6, fig 12) include these teeth from the Calvert and Pungo River Fms. as C. priscus (AGASSIZ 1843). Purdy et al (2001: 151) reported five teeth from Pungo River units 2-4 and attributed them to the extant taxon. The teeth are usually fairly small and closely follow the above description of Recent individuals. It should be noted that Recent teeth tend to have a broader cusp relative to height and the distal shoulder meets the main cusp more apically than seen in Pungo examples.

When evaluating a large (i.e., 100) group of collected Pungo River specimens, certain iconic tooth-designs can be readily recognized; however, when attempting to identify all specimens, many teeth become ambiguous.