The great white shark is an iconic apex predator, known largely for its dentition. The teeth of Carcharodon carcharias are adapted for a diet of marine mammals and large fish, reflecting millions of years of evolutionary refinement. Examining the structure and function of these teeth reveals an efficient biological cutting instrument.
Defining Physical Characteristics
A great white shark tooth is recognizable by its broad, triangular shape, which serves as a cutting edge. The maximum size of a modern adult tooth ranges from about 1 to 2.5 inches in length, though some specimens can reach up to 3 inches. This tooth is a wide, flat blade designed for slicing through tissue instead of piercing it.
The entire edge of the tooth, from the tip down to the broad root, is lined with fine, uniform serrations. These serrations function like the edge of a steak knife, enabling the shark to saw through tough skin, muscle, and bone. The root structure is distinctive, featuring a wide, robust base that anchors the blade securely into the shark’s cartilaginous jaw.
The teeth in the upper jaw are broader and more symmetrical than those in the lower jaw, which are narrower and more pointed. This difference allows the upper teeth to act as the primary cutting tools while the lower teeth serve to hold the prey in place. This combination of shape and serration is essential for effective predation.
Identification: Distinguishing Great White Teeth
When a shark tooth is found, its color often reveals its age. Recently shed modern teeth are white or gray because they are composed of unmineralized dentine and enameloid. Fossilized great white teeth are usually stained dark brown or black due to the absorption of minerals from surrounding sediment over thousands of years.
Distinguishing a great white tooth from similar species requires attention to detail, particularly when compared to the Mako and the extinct Megalodon. Mako shark teeth are long, slender, and pointed. Most significantly, Mako teeth lack the serrations that are the hallmark of the great white tooth, having a smooth cutting edge instead.
The comparison with the Megalodon tooth highlights the difference in scale and structure. Megalodon teeth are vastly larger, often measuring over four inches, and possess a more robust, broader triangular shape. A key feature for differentiating the two is the absence of a bourlette on the great white tooth, which is a dark, chevron-shaped band of enamel found between the crown and the root of a Megalodon tooth.
The Tooth’s Role in Predation
The triangular, serrated design supports the great white shark’s macropredatory feeding strategy. The broad, serrated edges allow the shark to inflict deep, slicing wounds and remove large chunks of flesh from prey like seals and whales. This structure is suited for a bite-and-release attack, where the initial strike causes massive trauma, allowing the prey to bleed out before the shark returns to feed.
This predatory tool is constantly maintained by a system known as the tooth battery, where teeth are arranged in multiple rows that function like a conveyor belt. When a front tooth is lost or broken, a replacement tooth moves forward from the row behind it to take its place. This continuous replacement ensures the shark maintains feeding efficiency.
The rate of replacement is rapid, ensuring the shark’s feeding efficiency is not compromised by dull or damaged teeth. This constant supply of fresh teeth is necessary because, unlike mammals, the shark’s teeth are not anchored in bone. Instead, they are embedded in the delicate gum tissue, making them susceptible to loss during feeding events.