Females are slightly smaller than males. The common dolphin has a dorsal fin that is almost triangular, in addition to small flippers and flukes. The beak is sharply divided from the lower forehead by a deep groove. The beak is elongated and pointed more than any other species of the same genus. The jaws on each side of the beak are lined with 20 or more small, sharp, recurved teeth, perfect for catching slippery fish.
Common dolphins are a colorful dolphin species.
The back is either black or dark brown, and they have a white or cream-colored underside. A dark streak stretches from the the lower jaw to the flipper. The flippers and flukes are the same color as the back, black or dark brown, and the eyes are encirled with black markings that extend to the beak. The most distinctive feature is a crisscross pattern which runs across the dolphin's side. It resembles an hourglass and divides the top and bottom colors.