Dolphin with fewest teeth

The dolphin with the fewest teeth is Risso's dolphin Grampus griseus. Typically, it possesses up to seven pairs of teeth in its lower jaw (mandible), specifically in this jaw's front region, but can possess as few as two pairs, and it usually does not possess any teeth at all in its upper jaw (maxilla). It inhabits tropical, subtropical, temperate and subantarctic waters between 60° N and 60° S. Its mandibular teeth are small, peg-like, and often badly-worn in older individuals, but the reason why it possesses so few of them remains unclear. It preys principally upon squid.