The Australian sea lion is a species of sea mammal. Males are enormously large, reaching a huge size: sometimes they can be 3 times bigger than females. Other distinctive features of these sea lions are: muzzles - tapered, long and narrow; sagittal crests on their skulls; extremely small ears, lying close to their heads. Males of the Australian sea lion are dark brown in color whereas females are silver. Young are also dark brown, having dark mask on their face and a pale crown.