Arnoux's beaked whale (Berardius arnuxii), also called the southern four-toothed whale, southern beaked whale, New Zealand beaked whale, southern giant bottlenose whale and southern porpoise whale is one of the species of Berardius. Arnoux's and Baird's beaked whales are so similar that researchers debated whether or not they are simply two populations of the same species, until genetic evidence and their wide geographical separation led them to be classified as separate. Little is known about their behavior due to infrequent encounters with live individuals.
Named Berardius arnuxii in 1851 for the French surgeon, M. Arnoux, who presented the skull to the Paris Museum of Natural History in 1846. Arnoux's and Baird's beaked whales, have very similar features and would be indistinguishable at sea if they did not exist in disjoint locations. Both whales reach similar sizes, have bulbous melons, and long prominent beaks. Their lower jaw is longer than the upper, and once sexual maturity is reached the front teeth are visible even when the mouth is fully closed. The Baird's and Arnoux's beaked whales are the only whales in the Ziphiidae family where both...
