What can we learn about an extinct animal from a single tooth? For example, a dinosaur. Many people believe that paleontologists often speculate when they describe in detail the appearance and lifestyle of these ancient reptiles based on a single find—such as a tooth. Even avid enthusiasts of paleontology sometimes doubt how so much information can be gleaned from such a small bone.

Studies dedicated to theropod teeth were published. As a result, scientists were able to determine the hunting behavior of Mesozoic predators, their diet, and the size of their prey. These insights were gained by analyzing the shape of the teeth, their damage, size, wear, and many other factors. It’s obvious that a scavenger, who wouldn’t mind feasting on bones, would have very strong and durable teeth with characteristic wear patterns. An active hunter’s teeth would be firmly anchored in sockets (special cavities in the jaw), and damage would manifest as parallel scratches, the result of struggling with prey. Identifying which dinosaur the tooth belonged to is not as challenging as it may seem. Let’s explore some striking examples.

The largest land predator in history must have had enormous teeth. This 15-meter-long monster, weighing over 7 tons, carried an impressive arsenal in its jaws. The front sections of Spinosaurus’s jaws housed 7-8 pairs of long, straight, conical teeth, with several dozen smaller teeth behind them. These teeth stand out among other predators’ teeth due to their size and smooth, conical shape. Spinosaurus specialized in hunting fish. It didn’t need serrations to tear flesh. Its sharp, long teeth pierced large fish like a needle, after which the fish was swallowed whole. The teeth of this super-predator could reach up to 15 cm in length.

To understand the stark differences between the teeth of the gigantic, fish-eating Spinosaurus and those of active land predators, let’s look at the teeth of dromaeosaurs. First, a 12-centimeter tooth is out of the question for an animal 1.5-2 meters long. The jaws of some dromaeosaurids were far more powerful than those of modern predators. Dromaeosaur teeth were weapons that could rip flesh from prey much larger than the predator itself. These teeth had a distinctive cutting edge with serrations, curved inward toward the jaw. The dinosaur would sink its razor-sharp teeth into the flesh, slightly twist its head to the side, and with a sharp backward motion of the neck, tear off chunks of meat. So, if you see a dagger-like tooth with serrations, it belongs to an active predator. Dromaeosaurs were relatively small, and their teeth were correspondingly sized, ranging from 2 to 5 cm.

But what if you’re dealing with a large predator? Of course, such a dinosaur would hunt prey of comparable size. For this, its teeth would need to be as reinforced as possible. Tyrannosaurus teeth had a D-shaped cross-section, various ridges for reinforcement, and were strongly curved backward. This design ensured that a struggling prey would not break the only weapon and vital survival tool the dinosaur had. Tyrannosaurus teeth are the largest in the history of land predators, growing up to an astounding 30 cm in length, including the root. The distinctive features of Tyrannosaurus teeth are their size and reinforcing elements, which are visible to the naked eye.

This gigantic African predator, comparable in size to Tyrannosaurus, impressed paleontologists so much with its teeth that it was named the “shark-toothed lizard.” We have two enormous dinosaurs with long, sharp teeth: Tyrannosaurus and Carcharodontosaurus. So how do you tell their teeth apart? The jaws of Carcharodontosaurus were significantly weaker than those of the “king of lizards,” and as a result, its diet and hunting style were markedly different, reflected in its teeth. While Tyrannosaurus’s teeth were powerful and reinforced, Carcharodontosaurus’s teeth were enormous razors. They were long, slightly convex on the sides, with very sharp edges. If you see a dinosaur tooth resembling that of a great white shark, it most likely belonged to Carcharodontosaurus, the most dangerous predator in African history.

The teeth of the herbivorous Triceratops are very distinctive. They were arranged in so-called batteries and were regularly replaced. While the ceratopsian beak was used for cropping plants, their teeth were needed to grind tough vegetation into a pulp. Up to 800 teeth could be present in the mouth of this Cretaceous rhino at any one time (during the replacement of old teeth with new ones). Triceratops teeth are hard to confuse with anything else. Worn teeth had flat, polished upper surfaces, while new teeth had small pointed tips at the top.

Nothing is more distinctive than the teeth of the giant sauropods. These enormous land animals underwent thousands of adaptive changes to grow to such sizes. One of the most important of these changes was their teeth. Sauropods abandoned chewing tough food and instead simply tore leaves from trees, swallowing them whole. Due to this diet, the titans of the Mesozoic developed a very characteristic tooth shape that resembled… a spoon. Yes, an ordinary spoon. If you look at sauropod teeth from a certain angle, they might seem like long, conical teeth of some predator, but inside the jaw, they are concave, making it easier to strip plants from branches. Once you see a picture, you’ll understand immediately.

Teeth are crucial survival tools for animals. From them, we can infer diet, lifestyle, hunting style, or even the type of vegetarian diet preferred. Sharp, straight teeth functioned like spears; for such predators, the main goal was to impale the prey on the tooth and then swallow it whole. Teeth that curved backward suggested that they were used to capture and hold prey. If such teeth had reinforcing elements, it meant the prey was large, and the struggle was intense. Large, broad teeth with characteristic wear or small pointed tips (like new Triceratops teeth) indicate a herbivorous diet. If the teeth have a “scooping” element, they were used to strip plants from branches.