Sharks shed thousands of teeth during their lifetimes, supplying a steady stream of hard structures to the ocean floor. Most teeth found on beaches are not from a shark that recently passed away, but are ancient relics that have been preserved through a natural process. These lost teeth become buried in the seabed, which protects them from decay and allows them to fossilize over millennia. The goal of any beachcomber is to distinguish this fossilized evidence of past marine life from the countless pieces of shell and debris washed ashore.
Key Visual Features for Identification
A genuine shark tooth is easily identified by its unique biological architecture, which sets it apart from common shell fragments or stones. The crown, the visible portion of the tooth, is coated in a durable, glass-like enameloid that gives it a smooth, polished texture even after eons of tumbling in the sand. This enameloid is significantly harder and more dense than a typical seashell, which is a good initial test for a potential find.
The overall shape is typically triangular or pointed, though the exact form varies widely depending on the species and the tooth’s position in the jaw. For instance, teeth from predatory sharks like the Great White are broad and triangular, while those from the Mako are long and slender with smooth edges. A closer look at the cutting edges may reveal serrations that indicate a predator that slices through its prey.
The most definitive feature is the root structure. Unlike the sharp, uniform edges of a broken shell, a shark tooth root is often lobed, V-shaped, or W-shaped, sometimes with a noticeable bulge or nutrient groove where blood vessels once supplied the living tooth. This thick, bilobed base is the clearest sign that the object is a fossilized dental element and not a piece of inorganic beach debris.
Understanding Color and Composition
The dark coloration of most beach-found shark teeth, typically black, gray, or brown, is a direct result of the fossilization process. When a shed tooth sinks and is rapidly buried in sediment, the absence of oxygen prevents the organic material from decaying. Over thousands to millions of years, mineral-rich water seeps through the sediment and into the porous structure of the tooth, replacing the original dentin and enameloid.
The specific color the tooth acquires is determined by the minerals present in the surrounding sediment. Teeth preserved in phosphate-rich environments often turn jet black or dark gray, while those found in areas with high iron content may display rich reddish-brown or orange hues. This mineral replacement makes the fossilized tooth much denser and harder than a modern, white tooth.
Prime Locations for Finding Teeth
Shark teeth are denser than most shell fragments and sand grains, so the ocean naturally sorts and concentrates them in specific areas. The most productive locations are often found along the “wrack line” or “shell line,” the linear deposit of debris left behind by the highest point of the receding tide. Within these shell beds, a tooth is more easily spotted because it is grouped with other objects of similar size and density.
Searching during low tide offers the largest exposed area of beach, but the best time to look is as the tide is going out, which allows you to inspect areas that have been freshly churned by the waves. Look for parts of the beach where erosion is occurring, such as near creek mouths, inlets, or exposed sediment layers, as the water action here is actively washing out and uncovering ancient fossil beds. Recent beach replenishment projects can also create temporary hot spots for collectors.