Do All Elephants Have Ivory Tusks?

Elephants have long and flexible trunks. On both sides of the trunk are two long and pointed ivory tusks. They are used as weapons to defend themselves and as tools to dig for food. But not all elephants have such ivory tusks. Big-eared African elephants, both males and females, have tusks. But among small-eared Asian elephants, such as elephants from Yunnan Province of China, only males have ivory tusks; females don't have them.