genitals are attached to a vestigial pelvis.

Sexual dimorphism is prominent in many species of toothed whale, including sperm whales, narwhals, many members of the beaked whale family and several species of the porpoise and dolphin families. In some of these species, males have developed external features absent in females that are advantageous in combat or display. For example, many male beaked whales possess tusks which are used