I added to the dolphin gallery Risso's Dolphin Grampus griseus. They are 8 to 12 ft in length. They have distinctive body markings and they have only 7 or fewer pairs of teeth in the front of the lower jaw, and typically none in the upper jaw.
This is a relatively robust dolphin with a rounded head, similar in shape to the more familiar pilot whale. They have an unusual external vertical crease in the melon (the organ in the rounded head used to direct sonar clicks) that runs from the front of the forehead to the mouth.
Adult Risso's dolphins are usually dark gray with extensive white scarring. The scars can be scratches, splotches, or circular marks and, in some animals, can be so extensive that the entire body appears to be white. This scarring may come from bites from other Risso's dolphins, squid bites, or parasites. Photography Copyright Francesca Scalpi