Ginkgo-toothed beaked whale
The ginkgo-toothed beaked whales gets its name from the shape of the male's teeth which are similar to the shape of the ginkgo tree leaf - a common tree in Japan near to where this beaked whale has predominantly been found and familiar to the Japanese scientists who named it.
The ginkgo-toothed beaked whales has a smoothly sloping forehead and a long beak. Its narrow upper jaws are sharply pointed and the lower jaws are highly arched. The adult male has a single pair of teeth close to the middle of the lower jaw; they are largely covered by flaps of skin with only the tip visible, and they do not protrude above the upper jaw as with some other beaked whales. The ginkgo-toothed beaked whale has a robust body and is less heavily scarred than other beaked whales. This is either due to the lack of external teeth and/or suggests that there is little aggression between males. Unfortunately, colouration darkens immediately after death making it hard to determine the colour of live individuals but it is believed that males are dark blue-black with white spots and blotches around the belly area, whereas females are mid-grey with paler bellies than the males. The flippers are small, pointed and narrow. Males have small white spots on their backs, sides and at the base of the tail which may be parasitic scars (for example, cookie cutter shark bites) rather than pigmentation.
Almost nothing is known about the behaviour of ginkgo-toothed beaked whales as the species has never been reliably identified in the wild.
Ginkgo-toothed beaked whales are known only from sparse strandings data, which indicates that they are widely distributed in warm temperate and tropical waters of the Indian Ocean and Pacific Ocean, with most records coming from Japan. Records from directed hunts and bycatch suggest that they live in areas of deep water. As with other species of beaked whales, threats to ginkgo-toothed beaked whales are thought to include noise pollution, marine debris, entanglement in fishing gear, and climate change. There is no worldwide population estimate and the IUCN lists this species as Data Deficient (2008).