The Kalahari Desert came into existence approximately sixty million years ago. The desert gets its name from the Tswana word Kgala ("the great thirst"), or Kgalagadi, Khalagari, or Kalagare, meaning "a waterless place". Over four hundred species of plants have been identified in the Kalahari Desert. The Kalahari's sand is better than most deserts at retaining water, and therefore allows for more plant life than most deserts.