90 mammal species become extinct in the period 1901-2000 than became extinct in the period 1801-1900.
Extinction is a situation in which something no longer exists. Their can be many reasons associated like species have been hunted to the point of extinction, scarcity of food or natural disasters.
Their are two main types of extinction firstly Mass extinction that has occurred only five times in history. The other is Background extinctions which occurs over longer period of time and are considered important in natural extinction rate.
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