Dolphins are very popular. Their social curiosity, skill, and friendliness attracts many humans to the sea, hoping for an encounter. Dolphins are cetaceans, part of the marine-dwelling order of the whales. The dolphin family is the largest group of the many toothed whales (like the squid-eating sperm whales). And the largest species of dolphin is the orca, also referred to as the “killer whale.” Porpoises are also part of the dolphin family, but they feature a distinct difference from their “cousins.” Around the world, the best way to tell them apart is the shape of their teeth.
In Northern California, you can usually tell the difference between a dolphin and a porpoise by their body structures. Dolphins along our coast have a pronounced jaw (commonly referred to as a beak), a bulbous head, and a curved dorsal fin. Harbor porpoises can be seen in San Francisco Bay and generally have a rounder face, no beak, a shorter and stouter body style, and a triangular dorsal fin. Even in Northern California, however, there are dolphins without beaks — Risso’s dolphin. In that case, scientists can look to the teeth for a positive identification.
The Teeth of Dolphins
Dolphins have cone-shaped teeth. Since their diet mostly consists of fish and squid, their conical teeth help to grab and hold on to their prey. They also use their teeth for other functions. For instance, dolphins use their teeth in an exercise to maintain their social hierarchy called raking. A dolphin scrapes its teeth against the face or body of another dolphin to reinforce who has what position in the pod (a pod is a group or family of dolphins). The scrapes are superficial and do not endanger the life of their fellow pod members.
The Teeth of Porpoises
Porpoise teeth are not cone-shaped, but spade-shaped. They also have rigid growths between their teeth called “gum-teeth”. Specialists believe these gum-teeth help in grasping slippery prey such as squid or octopi. Compared to dolphins, porpoises are timid, and not as curious about humans. If it helps, you could think of dolphins as extroverts, while porpoises are introverts. Porpoises also live a more isolated life. Dolphin pods can number into the thousands, but porpoises tend to be alone or in small groups.
Both dolphins and porpoises are homodont, meaning they only have one type of tooth. That works form them, since they generally only eat seafood. Humans are heterodont, meaning we have multiple types of teeth. In fact, we have four different kinds of teeth: incisors, canines, premolars, and molars. This fits our lifestyle as omnivores.
Unlike the whales, we take care of our teeth by brushing them for two minutes, twice a day. We also have specialists to help us maintain all four types of teeth. Take advantage of our team at the Placerville Dental Group. We make sure your teeth are the best they can be, so your smile can show off all four types of your teeth. That way, if you meet a dolphin or porpoise out at sea and smile at them, they might smile right back – and then you can look close to confirm if they are a dolphin or a porpoise!